First off let me say I know nothing about traffic laws in your state, so I'm just spouting opinions and make no claims that they're more or less accurate than any other person's opinion.
But I would recommend you look into some small aftermarket blinkers for a few reasons.
1) Why give a cop a reason to get you onto the side of the road. I'm sure we've all run across the ones who are just looking for an excuse. You could be riding right NEXT to a cruiser bike with no signals and they would pull you over first because they are looking twice because your bike doesn't "look" legal at first glance.
2) Even if it is a "fix-it" ticket for no signals, what if the cop initially pulled you over for something else (lets say speeding because we all do it) and just uses that to pile on additional citations. He could go after you for speeding, failing to signal, no signals on the bike and so on. Sure it's an a-hole move, but he (or she) wouldn't be the first cop to do it.
3) Whatever your reasons for not wanting the signals (durability off-road, weight, cost, looks) they're all minor compared to your safety. You said you're commuting on the bike now. I don't know how far your commute is, or what the traffic conditions are like, but I would imagine that you're risk is reduced by having signals on the bike. Even if you're reducing that risk by just a little bit then it would seem worth it to me.