It seems fairly obvious that you like to be physically controlled, and the fact that it excites is normal. Even going to the lengths you've described, but I have to agree with the others. The safe words don't take away his control, but maintain your safety. And it's not always about right now.

I trained in martial arts so I could defend myself, should the situation arise. It never has, and I doubt it ever will, but my safety is there. It says a lot about him that he is good enough to read the real changes in your attitude, but what about tomorrow. If he misses the signs, or you really want to continue things can get a little muddled. Likewise, if you have to use your safe word and he doesn't stop you know things have gotten out of hand, and you need to be seriously thinking about you health and safety.

I would hate to see you get seriously hurt because a silly misunderstanding, or worse. And I will stop carrying on now.