Jim's just too broken down of a unit and not worth to kick at....that's just beyond plain broken to hell and not making it's way back by the looks of things.
So did that shit start in childhood or what?
When your cock is under lock and key, and you know the person who beats you senseless/is your source of "Law" has the key? If your libido has the potential to run away with you... you might be surprised how your behavior can shift with one compared to being without one. Having to have "permission" (or lockpicking skills) to even just masturbate can change someone.
I'd avoid wearing one personally because I figure it'd have whoever my partner is in that scenario not try as hard.
I can't speak to say that they care about no ones pain but their own. They are self centered and care only about things that have to pertain to themselves. I do think they are capable of relating to others pain, though they will most likely find away to loop it back to themselves and their own experiences.
As far as Jim's case is concerned, yes, I do believe he's insecure and makes up for it by constantly insulting others and trying to belittle them in an attempt to make himself feel better which translates to insecurity.