We all have our opinions of everyone's back story. Given to us from the game all we know about Kenny is that he does have trust issues (Your either with him or your against him). We know he is a fisherman with a boat, and we know he does live in Florida normally. There are small
biographies on the TTG website. Kenny's biography is "A likable, but nevertheless flawed man, Kenny is a fishing boat captain from Fort Lauderdale, FL. He is a sharp, hard-working guy who likes to take action and make things happen. Kenny’s family is his top priority."
I believe until we know more it's up to the players to put together peoples past depending on how they react. The OP may be right, maybe not. His trust issues may stem from work related problems, or maybe something else. Maybe Kenny has a guilty conscious from Larry or maybe from something else that makes him the way he is?
My own reason why I think Kenny has trust issues is when he discussed with Lee when they first met that someone tried to grab his boy and he was "On the fucker in about two seconds."