You're fine, as far as the escorting goes, incall or outcall.
He (or anyone else) can legally gain from your work (i.e. be paid rent or act as security)
provided that they do not control your work.
(This was one of the changes in the Sexual Offences Act 2003 which got rid of the old laws often misleading referred to as the laws against 'immoral earnings'. Now, you can control someone else's prostitution, or you can gain from it, but you can't do both.)
I can see that being both the landlord and the 'person on the premises' could make it look more likely that he does control your work, so you need to be very very clear about who's in charge (you). You pay him, he provides what you paid for and the less contact he has with clients, the better, really.
If he does not own the property, but is renting it himself, he'll be breaking section 36 of the Sexual Offences Act 1956 which makes it an offence for a tenant to knowingly permit their premises to be used for "habitual prostitution", even by a single person, even though that person is not doing anything illegal. In practice, he'd have to be staggeringly unlucky to be caught by this.
As far as dominatrix work is concerned, R v Brown (i.e. the Spanner case) says consent is worse than irrelevant for injuries inflicted for sexual pleasure, if they are more than 'transient and trifling'. Hence anyone inflicting them is guilty of assault.
Lots of pro dommes make a point about saying they don't have 'sex' with clients. That's mostly trying to pretend they're not prostitutes, because these are services of a sexual nature. Selling them is legal, up to the point that you cross the Spanner line.
The basic way to avoid trouble is to make damn sure you don't cross that line. You don't want to leave marks, basically. Humiliation, bondage, pain play, watersports - fine. Hitting them with something that leaves marks for more than an annoyingly unspecified time - risky.
The good news is that lots of clients don't want to leave with marks either, due to not wanting to have to explain them away to someone.
(Isn't anyone allowed a weekend off, especially when this site was off the internet for a while during that time?
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