I have studied the game mechanics to some extent, despite not having played the game (other than to test some stuff). I've also now watched a couple speedruns of the game.

If I do ever play Pool of Radiance, I'll probably use a strategy like the one I mentioned.

On the other hand, when I get around to playing these games, I'll probably start with Secret of the Silver Blades, in order to avoid Pool of Radiance's issues with things like healing being way too slow, and Curse's bad game design of throwing you into an area where you can't train for a while immediately after the dual-class mechanic is first introduced.

Also, I have played Dungeon Hack. (Hint: That particular game is biased in favor of clerics.)

One option with Pool is to play the FRUA adaptation--it has all the features like Fix that weren't in the original.

Another option is to get the Dragonlance series and start with Champions--the mechanics are a little different but the plot is pretty good and there's even kind of a strong female character.

I would not advise starting with Secret--it is everyone's least favorite game, and the end in particular has an immensely boring slog through ice caves full of large numbers of repetitive battles.

I don't mind large numbers of repetitive battles; in fact, I sometimes enjoy playing games like the NES Dragon Warrior, where for much of the game all you do is fight the same enemies over and over to accumulate enough experience points to level up. (For those not familiar with Dragon Warrior 1, I note that the game is open world, but a beginning character will not be able to survive long except close to the start; also, XP and gold is accumulated slowly, so it will be a while before your level is high enough to explore the more remote areas of the map.)

Late to.the party but...
Payed it a dozen times over 30 years.

I am probably in the minority but I don't like to take characters onto the next game
I know the importance of fireball but never liked having a pure magic user as they are so weak at first.
Don't love 3 class characters as much as I used to.
When I was young and single I could play and level up for hours.
Now that i am old and married my time is more limited I prefer this setup:

Fighter..Human Male
Cleric..Human Female
F/T..Dwarf Male
F/M Elf Male
F/M Half-Elf Male
Last spot has been either a F/C or C/M femaleb depending if I want a 3rd magic user or the additional fighter.

I know there is no in game reason for a female.character or dwarf and minimal use for.a thief but I like having them. Just feels "wrong" not to.

Typically for all gold box games, it's 2 Fighter Types, a Thief (or F/T), a Cleric, a Mage, and a wildcard.
I've found it's always best to take humans. That way you never have to deal with the level cap, except for the game's.

Some more thoughts:
1. Always make at least one character female. For non-fighters (ie classes that cant do 18/00 str), the gender is totally irrelevant, and some plots require a woman be in the party (ie the Swanmays in CotAB)
2. As tempting as it may be, stay far, far, FAR away from the Fighter/Mage/Thief multiclass. Your hitpoints will be absolute garbage, it will take you forever to level him up, and he ultimately won't do any of the three classes well in most games. He'll easily be the weakest member of your party for 99% of the game. Plus you'll have the racial level cap anyway.
3. Dual Classing is not always worth it. I know the payoff is the "human multiclass" character, but it usually takes most of the game to get there, and its rarely worth it.
4. If the game involves a lot of undead, a paladin is always worth it. If the game is going to be in the wilderness, a Ranger is a great idea.
5. Don't make every character do the "one handed weapon and shield" thing. The Gold Box games LOVE giving out powerful two-handed weapons. Make sure at least one of your fighters favors two-handed.
6. Don't count out the non-sword weapons. Most of them stink for Large damage, but you'll be fighting medium sized foes most of the time in most Gold Box games. Many of the miscellaneous weapons do more damage than the swords against M size. Don't throw away that +2 spetum.

I'm no gold box expert, but I just played through POR for the first time and I would probably use this party if I was looking to blow through it again with the "most powerful" party, maybe with a full cleric instead of C/M. Stinking Cloud is so OP, most of the time it would be what I want to do on a combat turn over just hitting one guy.

Also to any Google travelers, it is true that thieves are indeed useless in this game. I simply walked into and triggered every trap in this game and never died. Maybe they're useful in the sequels but not POR.

Hold on. It's true thieves are definitely not absolutely required in gold box (I think in any game in the series), but they do have some uses even in Pool of Radiance.

You're right that the traps in the game are not major threats. Still, did you complete the Cadorna Textile House quest in the way I would consider "best of both worlds?" i.e. get the Cadorna family treasure and get rewarded by Phorphyrys for (apparently) bringing back the treasure intact? To pull this off, you need a thief. Specifically (spoilers), a thief needs to climb down the well in the north part of the Textile House and make contact with the thieves' guild there. Then, bring the unopened treasure to the well and the guild will give you (most of) it and replace the seal so Porphyrys won't know you opened it.

Like almost all the quests in Pool, you certainly don't have to complete it to win the game, but for those who are interested, again you need a thief.

Another thing that doesn't work so well in Pool but works better in other gold box games is backstabbing. Players seem divided over whether setting up backstabs in combat is worth it, but it certainly has plenty of defenders.

One thing almost everyone seem to agree on, though: it's almost never worthwhile to use a single class thief. Thieves should be multi-classed. This should probably be at least with fighter, so the thief can make more effective backstabs, though if you're playing into high level games, it's probably best to combine with magic-user as well.

Further spoilers:

In the Commodore-64 version of this game at least, the XP for the treasure gained is within a random range (due to the variable value of the gems and jewelry). The thieves take a full half of the monetary treasure, so you actually get *more* XP (on average) and more treasure by opening the treasure yourself. There are no consequences and Porphyrys is a traitor anyway.

* In the guide by SJ Lee, he doesn't mention the variable XP from treasure containing gems and jewelry, so it might not work that way in the DOS version? He mentions 1200XP from the treasure if it's opened by thieves (which is the maximum you can get in the C64 version), but only 1943XP if you open it yourself (in the C64 version, you can earn up to 2400XP by opening it yourself). In the C64 version, the reward from Cadorna if you don't open it yourself is a maximum of 1000XP, whereas in the guide it's stated to be 833XP.

Oh, goodness, I always play as a slightly morally gray good party. Well, maybe in my current playthrough.

I'll give my two cents on the topic. My first time in this one (coming over from the Krynn series) I was worried about level limits, so I did

2 Human Fighters
2 Human Clerics
1 Human Mage
1 Elf Mage/Thief

For my current playstyle, looking at this game alone I consider the optimal party to be:
2 Dwarf Fighters
1 Human Cleric
1 Human Mage
1 Half Elf C/F/M
1 Elf F/M/T

The Dwarfs: "shorty" saving throw bonuses don't come into play very often, but when they do you're usually very far from civilization, and the circumstances are unpredictable. The only place max Dex 17 is a total loss is in the Graveyard, lacking Str 18/00 is probably offset by bonuses to hit Goblins and Orcs, and once you get 1.5 attacks per round you won't even notice it. Fighter limit of 9 isn't a factor in PoR, in other games obviously it is. The other games I obviously would say Human Ranger and Paladin are better.

The triple-classes: It's incredibly frustrating to reroll constantly trying to max out their HP, and they belong in the back of formation. However if you grind them to Fighter 7, they're insane. Even if you don't, what they give you almost the entire game is they can perform an initial magic salvo and, unlike single-classed casters, appreciable cleanup afterward. Your Thief and 2nd mage roles have armor and a bow while staying well in the back row, so despite being your opportunist they're never useless. And C/F/M has an initial magic salvo to give more often than F/M/T does.

It's been several months since I played Pool of Radiance and I didn't know about variable xp at this point in any version of the game, so it would be hard to check. However, you are right that Stephen Lee's guide is for the DOS version.

It's not just this particular location, in many other places the guide states a fixed number of coins, gems, or jewelry, but in the C64 version it is a variable number. (I want to say it's *always* variable in the C64 version, but I don't want to check every single instance to verify that there aren't a few cases where it might be fixed, but it's definitely variable almost every time there are coins, gems, or jewelry.)