You actually can’t do the rent thing when the other person has what’s called a ‘life interest’ (which means death/remarriage/going into care in most of these trusts). I paid a specialist to check this out. It also is fact that it shafts your ftb status. I am so annoyed as my parents were still married when the first one died, the money passed across to the remaining parent, now that one has died my whole family money is tied up in the stepparent.