I have my wife give me a BJ or HJ while incorporating anal dildos or vibes about 2x a month. I'm not so worried about 'wrecking my butt' as you put it because the toys we use are modestly sized - although I've worked my way up to a size that appears about the same size that I am - about average as penises go.

First of all, don't worry too much - you're probably not going to "wear out" your butt unless you do very prolonged activities (think hours) or very extreme activities (think fisting). Secondly, do listen to your body. If your butt is telling you it wants a break then give it one - also don't rush too much.

I do anal play (I provide the anus) alone or with my wife whenever I/we feel like it. Sometimes once a week, sometimes every day for a week, sometimes less than once a week. It's all what we want and what feels good. I do listen to my body and give my butt time off when it asks.

goes in waves, sometime a lot sometimes very seldom

2-3 times a week