In a prior post, a question was posed regarding the mechanics of a 5 yr commercial loan with a 20 yr amortization. In the respones, it was stated that the banks refinance after 5 yrs to avoid "interest rate risk" but this was not necessary with residential mortgages.
a) why not?

If the rental property that I am purchasing is a single family residence or condo, should I be able to get a residential mortgage?
c)What is the benefit of a commercial loan over a fixed rate 20 yr mortgage on the same property?
Thanks