Define "comfortable." In a lot of way D/s is like vanilla, and in some ways it isn't. Yes, this is all about exchange of power, where the sub/slave cedes power to the Dom/Master. But how much power is something they both have to agree on.

So, is it out of line? Not necessarily. I'm sorry but it is hard to answer your question directly. I can tell you that I think such a limit is not uncommon for most people.