So I made myself some party builds I would like to play. Started the game and went to the character creation skill.

God damn that dice rolling. I've spent 20 minutes on rolling a dice to get a monk. And that was just the first character. So I decided to go with premade characters.

Can you play through this game with the default party? Any practical tips that go beyond the handbook?

Any party with at least someone to cast mage and priest spells will do. Some parties will require more levelling up than others.

Carrying capacity is set at the beginning and never changed afterwards so put leftover points into strength and vitality (grants half the bonus). Don't bother raising int and pie at character creation for any class, even for casters. Personality is useless. For dex and speed only the current stat matters, not the value you started with so they are secondary. Even starting with 8-9 will most likely let you reach 12 which is enough to get the maximum number of attacks per round at high levels.

Spell regeneration rate is also set at the beginning and never changed, with 16+ vitality you get a bonus to it. Far better than what you get for extremely high int and pie.

Never put points into weapon skills, they will raise on their own just by using them. The same applies to most other skills like music, oratory, ninjutsu and mythology.
The only skills worth putting points into are the academic casting skills (thaumaturgy, theology, theosophy and alchemy) and kirijutsu, eventually also scouting (can be replaced with the detect secret spell or by searching more) and thieving skills.

Have your monk hide as much as possible in combat and fight without weapons, this way ninjutsu and hand&feet will raise and the character will become far more effective. I'd put all skill points into theosophy until it's 54 (for getting level 4 spells) and afterwards the rest into kirijutsu.

The pregenerated party is playable but you can do much better, most characters had stat rolls of only 5. It will definitely get better if you replace a fighter or mage with your monk, no matter the stats.

Some classes are very hard to roll, I recommend creating a dwarf valkyrie which needs only a roll of 9 but a higher roll is better for more carrying capacity. You could even start with a dwarf priest who has 9 dex and 10 speed and when they are raised by one at level ups switch to valkyrie. Or if you start as fighter to switch later you could start with lower personality and piety too to get more carrying capacity by raising strength at creation.

A felpurr bard is also easy to roll and makes the beginning much easier.

Thanks for the tips. God bless you.

* Except for the very few permanent benefits like carry capacity (arguably a bug, anyway; IIRC W7 no longer has this behaviour), the initial stat roll has no bearing once you make your first class change (the stats you get after a class change are fixed, and always are the lowest stats allowed for that class/race combination). Even the guide writers that utterly *demand* you roll an 18 bonus on everyone to start with really only benefit from extra CC, since typically they use class changes :)

About the only way to get an unusable party would be if *everyone* was so weak as to not be able to carry necessary quest items (a few of them are pretty heavy, as in about 50 or so).

* Any skill you have at least 1 point in, and any spell you learn, is yours to keep and continue to invest in regardless of future class changes (keep in mind, however, that no matter how high your weapon skills are, it is still your current class that determines your available equipment options, and that no matter what your scores are in the four casting skills, you can only choose new spells from your current class's naturally available spellbook).

* Once you get to the Mines, a priority should be to find your way to the room that has multiple beneficial fountains. If you want a powerful party, spend several hours training in this area (to trigger encounters without having to venture far, you can simply spin in place) gaining the necessary XP and making desired class changes.

* Once you have access to ready means of grinding and restoration, you really want to keep swapping around your classes once you're level 7-9 or so in your current one, if possible. XP is old school AD&D exponential style, so the amount that would have gained you just one more level in your current class can instead gain you another 7-9 levels in a different one, complete with skill points, spell picks, and most of all spell point increases (and you really really really want massive spell point pools on your casters as a goal - SP regenerates at a painfully slow rate, resting is always risky, the high power spells you'll need to cast late game are very expensive, and in the late game areas you will no longer find the SP restoring fountains, so you'll be on your own to maintain resources!).

Don't worry about class switching, it's totally unnecessary, costs time and XP. If you created a character with class switching in mind don't do it too late, in the end the level in the final class is most important.
If you switch classes again and again be aware that you'll waste so much time reloading that someone without class switching at all will have finished the game faster with higher leveled and more powerful characters.

Time doesn't pass during the game so you can search for extra random battles any time as much as you want if you want more power, if you play without a walkthrough you'll have more battles because you have to explore more.

Thanks for the tips. At the end, I crafted my own party, as follows:
1 - Lizardman fighter. Sword/shield/mythology
2 - Human fighter. Sword/shield/scouting
3 - Felpurr (female) thief. Sword/dagger/skuldugger/legerdemain/ninjutsu
4 - Hobbit bard (dice rolled). Bows/sling (depends on ammo available)/music. Gotta say, a lute playing made all early encounters MUCH more bearable.
5 - Elf mage. Thaumaturgy. Fireballs are really efficient so far.
6 - Rawulf priest. Pole&staff/Theology.

Is having two fighters with the same type of weapon really bad? NPCs encountered so far didn't really have nothing better to offer me. I'm going to swap one's weapon of choice eventually, any tips?

I've just cleared out the Catle and entered the Mountain region. It was so satisfying to play it through not really knowing what kind of encounters are in the game and how it is played, and getting used to the UI. I tried to do everything all by myself, and even if wasn't possible for me (I had problems finding an item that lets you decipher the Deadman's Log - I thought you can't enter those prison cells from both sides). Other than that, it was surprisingly logical and informative to me interact with NPCs in the Castle and to even find Snoopcheri without asking the Internet (so no "oy, where's the puzzlebox?" syndrom for me).
That's my first hardcore-old blobber experience (I played Wiz7, but it's so much more "next-gen"), and it's a blast so far.

It's no problem having your fighters use the same weapon type, when you equip another type they'll increase the skill quickly just by using it. You can switch weapons if you want to max another weapon type.

Consider dualwielding with your fighters when you're high enough level, with <12 spd fighters get an off-hand attack at level 9, with 12+ spd even earlier. The weapons which can be used off-hand (like bec de corbin) aren't as good as the best main hand weapons but still do make a difference.
It depends on the items you've found whether 2-handed, shield, or 2 weapons is best.

Have your bard put all skill points into thaumaturgy just like your mage so he gets high level spells too, music and weapon skills will raise to 100 just by using them in combat.