Wax Key is only for those who don't want to constantly have to break into the same place using picks.
I disagree about the Lockpicking tree being useless. Picking locks without the guards notcing is nice and then you have Treasure Hunter and uh the other one for more gold in chests-love em.
As for the Speech Tree I find it usefull too, granted I do not get the stuff on the right side, but I do put points on the left side. Having to sell any item to a merchant is highly useful. Then when you invest in a merchant the Riverwood trader is the only person you need to sell too-which is very nice and simple.
You may complain now you have too much gold, more then you know what to do, but maybe the DLC will give you something to do with that gold.