Most people take the Paladin for healing rather than the Knight. So a non-healing Paladin would be a weak Knight.
Druids give you elemental and cleric schools of magic. Druids in MM6 are almost too powerful and in MM7 pretty useless. So a K,D,C,W party would be strong party. In MM6, the fighter pretty much is a reserve of hit points for the other players by the end of the game.

I always spread out the skills so that the skill levels between characters are even.

And it makes sense for certain characters to have certain skills. Like perception and disarm for archer, merchant for paladin, identify for sorceror...

Feel free to buy every skill/spell for every character that can possess it (I do, even diplomacy). However, only one character ever needs to spend skill points in some skills (ex. ID Item), because you can only ever have one character at a time take that action. After the first Disarm guy has opened a chest, the trap is gone (regardless of disarm's success or failure); the second Disarm guy will never use his points in the skill. It is less relevant in this game WHICH character raises the skill, just have only one character do it. Feel free to designate the Paladin as your Merchant, while someone else does ID, a third does Repair, etc. Or you could put all of the misc skills on the same guy.

The principle is to be aware that skill points are effectively a limited resource, and to plan how each character is going to use their points so you can cover all of the party's needs. The higher you raise a skill, the more skill points it will take to raise it again.

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A Druid is perfectly viable, and I considered pointing him out as an option, but he is going to take the skill point problem of the Cleric and Sorcerer and he is going to magnify it. No one else gets as many magic skills as the Druid does, so he can't really afford to be spending his points in party utility skills like Repair Item. A little goes into weapon/armor skills, and he'll want Meditation and Learning, but after that he's mostly going to be raising his magic skills. I would not recommend trying to give him many (if any) of the party misc skills. A Paladin and Archer can effectively split the misc load, since neither one would be a primary caster of their available magics.

If you take Druid (D), Cleric (C), and Sorcerer (S), then you could swap the Paladin (P) out for a Knight (K). The Knight has better HP, and he could take over all of the Misc skills without much issue since he doesn't have anything else except weapons and armor. The trade off is that he would never have the option of becoming a 3rd string healer (the Druid will be fine as a back-up healer); you don't really need a 3rd string healer as anything except a minor convenience, so this isn't a big draw-back. One other note: you place the Druid and Sorcerer in some competition for equipment; this isn't too bad as long as the Druid takes one weapon type (probably Dagger) and the Sorcerer takes the other (probably Staff). Finding two decent Leather armors isn't a big issue.

Once again, just split which elemental magics the Druid and Sorcerer will work on, at first. The Sorcerer could take Air and Water as the more MP intensive fields, while the Druid takes Fire (torchlight) and Earth as less MP intensive work (the Druid will be spending MP on healing spells as well). Fire and Air should probably go to different characters, since those are the better damage dealing elemental magics.

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You'll want your main casters (C, S) to eventually have all of their respective magic skills at Master level. The only exception I'd consider would be Earth; I don't remember any really useful spells being in that class. Additionally, your back up healer should master the Self magics eventually, though they don't need to invest any skill points beyond attaining mastery. A big part of the back-up healer's job is to fix the main healer when something bad happens to the main, like curse, paralyze, death, or eradication. Your cleric can't resurrect himself, after all.

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One last note about stats: at character creation, Intellect and Personality should only be given to people that actually use them. Intellect boosts the amount of spell points for Archers, Sorcerers, and Druids. Personality boosts spell points for Paladins, Clerics, and Druids. The Knight gets zero (direct) use out of either one. If the character doesn't use them, then pull points out of that stat and put the points elsewhere. Go ahead and use the Divine X potion even on characters that don't use the stat, because everyone can benefit from the extra skill points attained by winning at challenge pedestals (you can use equipment and stat boosting spells to get the necessary total, too).

Everyone can make (varying) use of the other stats, especially Endurance and Speed. Speed affects how fast you can take actions (regardless of action), while Endurance both gives bonus HP and determines how far into negative HP you can go before you die.

I'll try to give you a bit of help. 3 out of 4 of your characters are magic oriented so you need to concentrate on developing their magic skills urgently. Having the Bow skill for all 4 is good as you really want to keep as many enemies at a distance as you can especially early on when you don't have magical WMD's. Your Druiid and Priest can both wear chain armour so get this skill for both as early as possible. I can't remember where but there is a set of plate for your warrior available early in the game but just in case, give him chain skill as well - also you'll find the Axe skill of great help later. I could probably advise you better on individual set pieces as I have played this one several times and i also have the Prima guide. If you feel you need any further help just post or contact me direct (colin.wheeler4@ntlworld.com). Good luck and enjoy!