Since the advent of NASD 05-50, several agents have asked me if they should become FINRA-registered representatives. If your goal is to work as a registered rep and broaden the number of financial arrows in your quiver, then my answer is yes. But if your goal is to sell only fixed annuities, then perhaps you should steer clear.
Looking back over the last dozen years, you find that FINRA (originally NASD) issued or reinterpreted a rule affecting the business of reps and broker/dealers every third business day. In the securities world, scrutiny and liability are far more evident than in the insurance world. Forget any thoughts of "innocent until proven guilty." In my own practice, I routinely received NASD notices citing a rule that one of my reps allegedly broke. Since then, FINRA rules have continued to proliferate to the point that it is very difficult to maintain a clean record.
If your main business is selling fixed insurance products, you need to disclose what you do, when you do it, and to whom you do it. Make sure you answer every U-4 question correctly because you have agreed "that I am subject to administrative, civil or criminal penalties if I give false or misleading answers" and FINRA is the body that defines what is misleading.