In my original build I had lockpicking, because I'm a compulsive looter. That being said, I'm confident you will not have any major issue leveling without it. Actually I think that pickpocketing will compensate the lack of lockpicking, at least in early/mid game. And if you really want some lockpicking, you can transfer skill points from throwing, tailoring, biology, stealth... The build performs really well in combat, so it is quite flexible.
Also, if you want to use vents, you can probably use a crowbar. Most vents can be opened with 8 STR if I recall correctly, so with one STR buff it should be fine (Regalia, Barbecue).