It's a lot easier to have cooperation with the Admiral if she has a place to come back to. As you said, they need that.
15% ?? That's quite a bit. In Southern California most property managers charge between 5 and 7%. I think that most are pushing toward 7. Our old property manager wasn't doing a very good job and raised his percentage to 7 so we switched to one for 6 and have been very happy. If a property manager is really good I'd consider as much as 10 but 15 is a lot.
Hell, if it makes me feel secure and that's the rate I'd go with it anyway.