If a thief steals any of my vehicles and trashes them I am screwed.
Not that I am disagreeing with you, buy in that specific example, how would you be screwed? I would assume insurance policies would cover the cost of damages if a car is stolen and trashed? Now, stealing your wallet or wife's purse and stealing your identity would be a real PITA to clear up, but recovering from the loss of a stolen vehicle wouldn't be that difficult.
Personally, I would have called 911 and reported the fence hopper immediately. Had he came towards my home directly or entered it, then well, do what you must. For all we know, the kid himself was running through a neighbourhood trying to hide from some thugs and was just going to duck behind the fence for a bit. Or maybe he was up to no good and was going to try to break into a house. We don't know.
I've got no remorse for Trayvon, as the facts rolled in, it was clear who the initial attacker was and that Zimmerman likely feared for his life and could not escape harm. In this case though I feel like the home owner may have 'jumped the gun' a little too early.