Below is a summary that has no legal standing. The complete bicycle code is at the end. That means no one can ride on your handlebars, rack, top tube or on your pegs. The law gives a cyclist the right to take the lane when necessary for safety. One when signaling but two when turning works well.
Bicyclists have the all rights and responsibilities of other vehicle operators.
The light is primarily so people can see you coming from the side where their headlights do not shine on your reflectors. Currently a red light cannot replace a red reflector. Texas law lets you signal a right turn by pointing with your right hand. Texas Transportation Code Sec. Method of Giving Hand and Arm Signals.