Also, Fannie Mae has 100% ironed out all of the terms and guidelines to these loans.  

Fannie Mae and Freddie Mac are searching for methods to open homeownership to low income borrowers.

Low down payment financing options: Aside from 3.5% minimum down payment FHA loans, Fannie Mae is rolling out a 5% multifamily conventional loan option next month. 

.), plays a big role.Generally, there are three main refinance options for BRRRR method investors: Conventional loansBank/credit union loansDSCR loansConventional loans are generally defined as loans originated under GSE (Fannie Mae/Freddie Mac) rules and guidelines and securitized.

Fannie Mae allows an individual to have up to 10 loans.

YMMV, I always just use the numbers/procedures/etc directly from Fannie Mae, ignore our internal company forms/procedures/etc, and start yelling at people if our company's internal stuff is incorrect (this amounts to an overlay, I was recruited on the promise that this firm has no overlays, so that's my leg to stand on when I'm raising hell :P ). 

Fannie Mae and Freddie Mac put that about at 43% (yes...I know they can go higher, but this is guideline).

Utilizing Fannie Maes new 5% down for multi-family I'd like to prepare to sell my SFH and house hack a multi-family. 

You might be able to squeeze a little extra cash per month by offering that option.FHA is great for 3.5% down but keep in mind Fannie Mae now allows for 5% down any 2-4 Unit and the PMI is typically lower than the FHA MIP plus No FHA UFMIP so you avoid that 1.75% finance charge.

If you don't plan to finance the initial purchase via cash then I highly recommend you look into an FHA 203k or Fannie Mae HomeStlye Renovation Loan.