A few questions about tools for an entry tech...
I've always worked in smaller, independent shops, so tool thieves have been few and far between, in my experience. I started out marking my tools long ago, but have since quit doing so. I know what's mine and what isn't, as do the other guys I work with.
My general rule of thumb regarding my tools is that I'm more than willing to loan you a tool (at least a couple times 8)).
But it's well known by those I work with that if I catch you with your hand in my box when it doesn't belong there, I'll break it off in the drawer. Thieves are among the most reviled of scum, in my book. TOOL THIEVES are below even that! I don't play around with it at all.
Paint will wear off eventually. Get an engraver if you're serious about marking them. But be prepared to spend time putting your ID on those little tiny 1/4 drive, 3/16th inch or 5 mm shallow sockets, Allen wrenches, picks, driver bits, etc. :-D