You can househack non-conventionally, but that's by renting the room out and the better way.

I am in Huntsville, voted #1 place to live by several publications such as Kiplinger's and USA Today.

In some cases they cannot pull the money out because it is now (Non-owner occupant) an investment and their credit union or bank may cap them at 70% or 75% MAX LTV.Nothing wrong wiht putting 10% down on a primary but look at the rates on both 5% and 10% usually when you have PMI built in the rates stay the same.

What I see is more non accredited or lower net worth who are burdened by debt will be drawn to these types of strategies.

(In the simple / non complicated scenario)- time ranges - in the best / simple case scenario how long should I expect this process to take? 

I think I would probably talk to an attorney tbh these business purpose non regulated loans do not have rate locks that have to be honored legally.. they can and do change them unilaterally.. borrower accepts counters or declines and loan fails. 

He has only done single family (non investment) properties.

Pecunia non olet"

Your best bet is to read information from public blogs that approach both options objectively.

A 4 bed, 1 bath is typically a non-starter.Improving kitchens and baths.