There is indeed a lot of variation in "4-6%" guaranteed. Which is it? Is your expected $72k the 4% number? Or did the salesman advisor convince you to think of the 6% number as the minimum?
I'm not saying this is a bad move in your situation....but it is almost always not the best move. BUt choosing a variable annuity seems to be that you still want to call this money "in the market," but also want security. And, as with any hybrid solution, it's not really the best at doing either of those things.
If you are looking for the ultimate safety net, I would ask why you did not take a simple fixed annuity (most directly certain in payout, if not the highest--particularly with current interest rates) or a life insurance policy, if your worry is about your untimely death? Both are still not typical (thinking of "extra" life insurance, since, as you say, you are already FI) but simpler and cheaper than your variable annuity.