Spukrian
Savant
There is a good argument for playing thief in Arcanum, but maybe not on your first playthrough though...
*Joining the Thieves Guild gives you a lot of special quests in all the major towns of the game that aren't available otherwise. Granted, 95% of them are "Go to place X and steal item Y without getting caught", but it's a good source of extra XP. And if you like the item you stole, you could just steal it back after giving it to the fence.
*If you have thieving skills high enough, you could just break into stores at night time and steal the items and money that you need.
*Joining the Thieves Guild gives you a lot of special quests in all the major towns of the game that aren't available otherwise. Granted, 95% of them are "Go to place X and steal item Y without getting caught", but it's a good source of extra XP. And if you like the item you stole, you could just steal it back after giving it to the fence.
*If you have thieving skills high enough, you could just break into stores at night time and steal the items and money that you need.