Yeah. All of the above.
And to be honest, I've had bobbers, choppers, and other custom bikes that don't have speedos, mirrors, signals, headlights and/or taillights, open pipes with too loud of exhaust, no front brakes, license plate mounted incorrectly and not lit, etc. Etc. Etc....
AND I've had cops stop and check out my bike(s) and/or even to tell me to open it up WOT at lights in traffic and say it's an awesome bike.... Never been pulled over at 2am for running a red light that won't change (illegal in Indiana)...
From my experience all of the cops I've encountered, talked to, and my 4 family members in local law enforcement that frequent my residence, check out my bikes, and hell, even go on rides with me (they also have "illegal" aspects of their bikes and other friends and family do). Won't generally pull you over UNLESS you're doing something really stupid or he/she thinks you are putting yourself or others in danger. Let alone give you a ticket for a first time offence for not having turn signals.
BUT if you want to be "safe than sorry" just throw some on there. Like teazer said, we don't have a lot of the silly regs other states have on WHAT the turn signals are. You can pick up turn signals for like $5 and spend a whole 5 minutes wiring them up.