So what do you think about the lockpicking skill and do you think any of the perks are useful?

From what I had read before the game release, I knew not to spend perks on lockpicking. To be honest, I haven't even really looked at the skill tree. I haven't had any problems with opening any door or chest I've come across. I can open master locks in about 10 tries where my skill is now, and vendors usually have about 6 or 7 lockpicks for sale. I have roughly 225 lockpicks in my inventory at the moment. I also tote around a 30% easier lockpicking set of light gauntlets around with me. Right now I have zero motivation to drop perks into lockpicking.

From a gameplay standpoint, almost completely and utterly useless, especially to take over other skills.
As far as RP goes, mildly useful.

Solution: Bring back Major and Minor skills. Major skills are combat oriented skills and raise your level by being used. Minor skills are non-combat skills and do not raise your level by being used. Minor skills thus have a more robust perk system as well as crafting.

Major:
-One-Hand
-Two-Hand
-Archery
-Destruction
-Illusion
-Restoration
-Alteration
-Heavy Armor
-Light Armor
-Conjuration
-Block
-Sneak

Minor:
-Lockpicking
-Speech
-Pickpocketing

Crafting:
-Smithing
-Alchemy
-Enchanting
-Spellcrafting

There's a mod which adresses the easy-lockpicking "feature":

http://www.gamesas.com/index.php?/topic/1296300-rel-the-fingersmith-mod-lockpicking-overhaul/

I've never taken a lockpicking perk and never will despite my erm... "habit" of breaking far more then my fair share of lockpicks on chests. Even master locks can be picked open by a complete novice and there are too many perks I actually want to waist them making novice and adept locks easier. I really wish I could craft lockpicks though or maybe a nice open lock spell.

No need of perks unfortunately the minigame is easy and there are too many lockpicks available.