When an offer like that comes along, it can be tempting, but everyone is right. So many red flags!
If you work from his place, which other girls rent out, it's a brothel and a landlord will be the least of your problems. It will empower him to threaten to call the police as well maybe taking big cuts from your earnings.
I say stay well away. Block him number, or set in clear firm boundaries and just copy + paste them. "No thank you, I'm happy where I am." "No thank you, I'm happy where I am"
xx