+1 on the fact that you'll just go nuts obsessing about your bike. I know the feeling, my car was badly vandalized twice in 10 months, once while parked in my secured apartment garage. It made me sick for weeks thinking about it.
Then, two weeks ago, some schmuck markered up my buddy's bike. Mine was under cover, 20 feet away and left unmolested. But now I'M worried about it
As to the weapon situation, well, this might get this topic too hot, but...trust me, having access to one and judicious use (plus "catching" somebody in the act) are all different things. I figure it's more for the eventual earthquake that will hit LA and the ensuing pandemonium. So, my advice is don't obsess on that one either
Bikes, thankfully, are somewhat cheap. It's not a 45k car we're talking about. I hope some of my reasoning helps put your mind at ease