I found a decent number of lockpicking chests near the beginning of the game, but very few later on that didn't have a key. However, Bashing chests and doors now is pretty terribly inefficient. You CAN do it but it's going to take a couple minutes of just straight bashing. Lockpicking gear has been enough for me, no points invested.
As for pickpocketing, its usefulness in quests and story is pretty much nil. I think there are a couple of alternate quest solutions that use it, but nothing mandatory or even particularly interesting. Pickpocketing could be a pretty big money earner, and with merchants restocking regularly and selling the best stuff, money is pretty valuable. In my testing, pickpocking is reliable (no save scumming necessary), and allows you to steal based on the base value (not merchant markup) of items up to between 2000 and 3000 per target. That can earn you some 6000+ cost items for free from every merchant. I'm not however sure when or even if the steal value resets, meaning it could be a 1-time thing per target.
It would probably be most efficient to simply respec your character for pickpocketing. With respec only costing 1000 gold and NOT unlearning any skills like it did at release, taking a "pickpocket spec" and then visting every major merchant could earn you a LOT of gold or free items.
