OK I'm at about level 9 and realised I probably made some bad choices with my character.

For thing, I made a ranged sneaky character. In Fallout 1, this seems entirely useless as sneaking doesn't affect ranged attacks even if I eventually (at level 18) pick the Silent Death perk.

My other big mistake seems to have been to pick the One Handed trait. It means my success rate with attacking with one-handed weapons (skill 108%) is fairly high, but the best non-energy weapon one is a max of 30 points of damaged (and even with a regular chance of 95% to hit, I'm not getting many crits). My energy weapon skill is about 40%, so even if I spend the next few levels pumping points into that, the most commonly available best one-handed energy weapon is still only a max of 35%. Now that I've picked up a plasma rifle I'd love to be using that.

So am tempted to slightly cheat and use a character editor to remove that One-Handed trait and put my points from sneaking into something more beneficial. Would anyone blame me? :)

Not me. ;)
Seriously, if you think it's okay, just do it. Problem solved.
Or you can also start all over. :D

Your assumptions are mostly wrong. :)

A sneaky ranged character is a very viable build. One handed weapons are not a bad choice unless you were intending to play a sniper, in which case you should always use rifles for the longer range. With a sniper rifle and a high sneak skill you can pick off your enemies with head shots from all the way across the screen, and they won't even react because they won't know where the attacks are coming from.

IIRC, Silent Death is a perk for hand-to-hand attacks, and has nothing to do with ranged attacks. It's value is dubious considering how steep its prerequisites are. Also, creeping up behind someone until you're right next to him is extremely difficult even with really, really high Sneak. Maybe you're thinking of Sniper or Slayer, which are the best perks in the game for ranged and melee combat, respectively. Sniper makes every hit a critical if you succeed at a Luck roll, and Slayer makes every hit a critical, period. Crits are what make you deadly in Fallout 1 combat.

You can't tell how good a weapon is simply by looking at the damage number. Different types of ammo have modifiers that make the damage number by itself very deceptive. I assure you, the best one-handed small arm in the game, and the best one-handed energy weapon in the game are both sufficiently powerful to complete Fallout 1.

If you want more critical hits aim at the eyes, this will increase the critical chance by 60%, this will make even non-energy weapons deadly.

GO FOR THE EYES, BOO!!!
GO FOR THE EYESSS-S-S!!!

:)