From what I see, lv 20 locks certainly have a key (or a puzzle switch), so they are not a problem. For lower level chests/doors (lv 5 or 10) you can just break them if you really have a hard time finding the key/switch. And you don't really need to worry about durability because you can attack with spells. This is one reason to get XP from picking locks.
However, if the game is to give XP for lockpicking, how much XP should it offer? Levelled to area/player lv/individually set? Not to forget how many ability points, which you get from hard-earned level, you have to spend. Ability points can be better spent elsewhere.
