Looking through the thief paths, I notice that these two abilities may fulfill the same need. What I'm not sure about is whether it's wholly unnecessary to take both if I want to be able to get into everything that has a lock.

My initial thought is that both do close to the same thing, but locksmith gives you a physical copy of the key, or you can make a copy of an existing key without the need for the lock to be nearby. The differences seem fairly slight, but can I choose only one and expect to not lose out?

I would prefer to leave off of locksmith if infiltrate is close to the same in efficacy, just to be able to dip further into some more useful general abilities. I'm looking to make a more RP oriented explorer type character so that, as a player with low area/object information, I can learn the item values (One reason I'm going into the mystic path, because lore by itself doesn't give you much information where statistics are concerned. It may be different once perfected but I haven't had the patience to find that out as of yet.) and the areas with relative ease. I would prefer to have identify, but mage characters don't appeal to me just yet as someone with low area knowledge because I likely won't have any idea where to look for ABS, which seem to be pretty critical for those types. Also, my gear knowledge, limited as it is, is more inclined towards physical damage types, so the mystic/pickpocket thief should hopefully be the best of both worlds as to what suits my goals.