A monthly premium is clearly allowed. The borrower’s monthly loan payment would include principal, interest, and the monthly credit insurance premium. The premium would be a pass through item. If you sell a single premium policy the borrower would have to pay the full amount up front.
A dwelling is a one- to-four-family unit. It may be rental property, but in order for Regulation Z to apply the loan must be for a consumer purpose. A mobile home is a dwelling. When coverage in the regulation targets a principal dwelling the agency drafting the regulations use the term “principal dwelling.”