I agree that it only needs to happen once to make it a permanent worry. But the point is that he doesn't appear to have reported anything. I've been burgled once and there have been subsequent (failed) attempts (one while I was in the house). I reported every incident though - did you not report yours?
And having been burgled, there is no way I would be sleeping with any exterior doors open!
He didn't report anything at Silverwoods it seems (though Roux asked about the spelling of the potential complainants names, making me wonder if that was relevant to anything coming later.)
But there are other options.
If OP experienced a crime as a kid or teenager, it would have been his parents or relatives reporting, friends could have reported if they were in a group at the time, it might have been overseas in Mozambique or Europe. My point is his alleged terror and paranoia may well have started long before Silverwoods.
If so, no amount of statistics saying Silverwoods is safe is likely to completely diminish his fear. (Remember the police arrived on the scene fresh from a burglary at a similar gated communty iirc)