it is likely that the individual(s) living there will be the mortgage holder and not the trust. Not 100%, but very likely. I doubt it will complicate your transaction.
On a side note. Any of you that have not established a trust for estate tax purposes should likely do it. I procrastinated waaaaaay too long, so this is a hypocritical piece of advice. However, if you have kids, you better get a will at a minimum. I didn't procrastinate that part.