MIP is very high (I live in San Diego) and while I've only been in my home (duplex, owner-occupied) for a little over a year, I have made some upgrades and the local appreciation might have me at around 85% LTV. 

Buying investment property isn't different than buying an owner occupied house in terms of the steps so ultimately you just need someone competent, responsive, who you connect with and who does what they say they will do.

Does anyone know how many unrelated tenants can occupy the downstairs while we live upstairs?

I did a 3% down owner-occupied FHA down payment, and had the seller pay me 3% back towards closing.

Have no idea where you are but buying an owner occupied multifamily (duplex to quad) is usually a terrific wealth builder.

I am looking at multi-family (2-4 units) and house hack it (owner occupied one unit).

I just purchased an owner-occupied property from auction.com is now in the same boat.

This is a 12-unit building - fully residential, 10 are currently occupied.

Three of the units are presently rented out, and while the rent isn't provided in the listing, it's safe to assume the rents are likely around the $1,000 to $1,300 range based upon comps in the area (I would personally assume on the lower end, but I could so very easily be wrong). 3 of the 4 units are rented out, with the fourth being purposefully left open in the case somebody wants to owner-occupy (how smart!).

Is it an investment property or owner occupied?