Hemaka: Properly developed rogue (str/dex than speed and meanwhile maxing stealth) will soon outperform fighter in terms of damage per turn. You'll find an amazing sword for him in Arnika. So imo you shouldn't change anything in your party - you'll find bard and gadgie rpcs later who, besides doing exactly the same things "yours" bard/gadgie would do, also add a lot to the game's immersion. Definitely worth taking and you'll be able to test all this junk/instruments you have.
kalirion: Hmm, I haven't been concentrating on his STR/DEX too much, but I can start now. I also haven't put many points into his Stealth. How do you "train" Stealth besides at level up time?
To train stealth, enemies need to target your rogue. That's really all there is to it.
Note that, as your Stealth gets higher, enemies will be less likely to target the character with the skill, so make sure your other characters have good hp/armor.
One strategy (that I do not recommend) that some players have used is the following:
1. Start the game with a solo rogue.
2. Get into a fight.
3. Keep defending until your stealth skill gets really high (90+). (This will take a while.)
4. After the fight, continue as normal.
5. Enjoy the fact that enemies will no longer bother to attack you...or get frustrated at them defending all the time.
6. At level up, change to a different class.
What happens is that the enemies won't attack you, so you don't need to worry about dying. However, the enemies will be defending all the time, and defending actually has a noticeable effect. As a result, battles will take a while but won't be threatening. I think you can see why I would not recommend the strategy.
It is really because of this sort of thing that I personally prefer to avoid classes with Stealth. Locks and traps can be handled decently by a Bard or Gadgeteer. (Why do Bards get that skill anyway? That has never made sense to me, even back in AD&D. That skill makes perfect sense on a Gadgeteer, however.)
Anyway, I personally advise not going out of your way to train Stealth; it will rise high enough on its own.