>>When driving in your car around other traffic, do you use turn signals to alert other drivers as to your intentions?<<
Absolutely!
>>When ride your bike around other traffic, do you use hand signals to alert the other drivers as to your intentions?<<
Absolutely. But unlike in my car, where I instinctively turn on my turn signals, I don’t signal when there are no cars around. Also, because I assume I am invisible to cars, I can have an attitude that my signal on the bike is superfluous, since I only do what I would do if the cars really could not see me. It is mainly a courtesy.
>>Ever gotten a speeding ticket and tried telling the cop and/or judge you were just being ‘safe’ by keeping up with the ‘flow of traffic’?<<
No. And I understand that police do not generally give tickets for keeping up with the flow. If I did, that is the defense I would use. Many have, and successfully.
It really is about safety and flow.
Courtesy, time of day or traffic conditions are not components of the law governing signaling your intentions while operating a vehicle on the road.
If you're (cyclists in general, not you specifically) are going to demand the right to operate as an equal on the road, then you're should be obeying the same laws as the other vehicles.
There are not any exceptions or exemptions for cyclists.