. . . then I would certainly take a scholar as a long-term option. It means that you need never put any skill points into Identify, and gives you a small XP bonus. There are all sorts of options open for the remaining slot. A low-level healer is one (I always thought the master healer was much too costly) until you've collected enough stuff and skill to make your own healing and curative potions. Depending on how you prefer to fight, you many want to take a smith to mend your weapons or an alchemist to mend your magic-boosting items.
A locksmith will boost your disarm skill (by 6, I think) until you find a decent item to do it; a burglar will boost it further but will steal some of all the treasure you find (you didn't believe him when he said he took "nothing" did you? )
An instructor will boost your XP by 15%, but considering that all your "party's" experience is going to one character, I would say this is a very low priority.
You might consider a merchant to boost your income in the early stages, but again, I would judge this is a short term option – money's not going to be problem for a one-character party once he gets going, until he reaches seriously high levels – and when that happens, I suspect promotions are going to be too costly then for even two merchants to help.
I wouldn't consider guides, pirates, etc. unless you're going for a speed run.