So Many Artisan QuestionsFollow

I am getting close to having to choose which artisan class I want to pursue. I have narrowed it down to Armorer or Alchemist. I am a Troll, so I know I would get the opportunity to boost my armorer skills later, which leads to my armorer questions.

How much do your racial triat boosts (i.e. Armorer for Troll) boost your skills? Is it a considerable difference? Does it improve performance, or does it give additional skills? Also, at higher levels, can you actually create something that you would wear above something you would find? Or at higher levels do you just create things to sell? Can you create items that give bonuses like +2 STR? Also, as an armorer can I repair my equipment?

As for Alchemists, what are the effects of some of their better potions? I am assuming they can create healing potions, poisens, resistance enhancing potions, etc.

Any help anyone can offer I would appreciate. I am really looking for an artisan class that will be useful throughout the game and not just a fun thing to do once in awhile. I am also looking for one that doesn't become useless at higher levels. Thanks for all the help!