If so, the hit up every single local bank because they will be happy to help (as long as you have good credit history and if you are just starting out then they are stoked to see a separate steady source of income and not all reliant on the new investments).

Although you'll be adding more debt with each property your DTI should go down, as long as the properties cash flow well. 

On the back end we use commercial 7 year balloons, but you should use 30 year conventional products as long as you can (you are limited to 4 and then 6 more with tighter standards, so 10 total per SSN - in case your ar married you could 2x).

Additionally, do I only need to live in the property for the first year, or do I have to keep living in it for as long as I have an owner occupied loan?

As long as you are aware of some of the complexities of this loan type and prepared to deal with them accordingly, you will be good.

100% agree with @Aaron K.I'd tell them that you are not willing to buy them out of their lease, but they are able to break it with no fees should they find another property.As long as they're paying rent, it's best to keep them in the unit.

Based on your #'s above the #'s work as long as rental income is enough to positively cash flow. 

These numbers can always change just as long as both of you make adjustments and update operating agreement.

I believe you can purchase an Airbnb property using a vacation/second home mortgage with 10% down as long as you have control.  

Yes it is definitely possible for you to get an FHA loan in her name as long as her income qualifies.