A typical flip will take 5-6 months from purchase to sale so I haven't had to re-negotiate the term length. 

Decide on minimum income, length of time in job, minimum credit score, prior LL references, criminal background criteria (read Seattle laws), etc.  

If the lenders are arm's length from you then yes, refinancing both liens would fall under rate and term and not cash out.

Both I and the seller agent spoke to the mother in length and she agreed over the phone.

In regards to renting to a relative, the important tax issue is whether the transaction is “arms-length”.

Most land lords and property managers that have been doing this for any length of time will not let a tenant push them around much.

Company owner says yes it is allowable, because it's fair market value, "arms length" etc, and my son is not an owner.  

Maybe, just maybe a 10-20% overall savings.That stated the only real advantage to going MOD is turnaround time, job site congestion (tradesmen tripping over each other and/or slowing each other down), length of time in  causing local congestion issues for local traffic, weather issues, material and equipment vandalism and theft issues. 

I don't know any tenant/landlord situation where a lease is involved and the landlord has the right to come stay at the tenants property & bring a friend for any length of time.

Average length of tenancy for multi-family is three years (I read that somewhere), but the tenants at our multi-family tend to stay in place longer.