If you are self-employed or cannot qualify conventional, you can use non-QM programs. 

I'm considering purchasing a condo that is non-warrantable (not eligible for conventional financing) because one owner owns too many units and there is a pending lawsuit against the HOA.

is there a vacant unit for you to move into?

Instead of buying 2-4 units buy 2 units in a BTR community. 

It is noise and so incredibly self-serving and obvious. 

Just make sure your building can be zoned for a multi-unit if you have a multi-unit.  

Much easier to delude one self into purchasing a "mentorship" program for $30,000 or more ("put it on your credit card; you'll make it back on your first deal so it really won't cost you anything") and believing that after a "3 day boot camp" you'll be able to compete successfully with people who have the education, knowledge, experience and track record and have been doing it for years.  

Hello, My multifamily unit will be renovated soon.

Buy a variety of asset class/ unit count properties.

I plan to self manage, but it's good knowing a middle tier management option between self managed and full property management - without a huge PITA factor :)