DSCR loan doesn't require seasoning and may be another option to look at. 

There are a lot of wholesalers who are buying lists of properties in foreclosure / default and do not realize this in many states is considered predatory.As taxes and insurance increase along with homeowners having equity, states will start to catch on to this and my guess is start going after more of these wholesalers.It will be an easy win for them as most wholesalers act as brokers illegally (do not do double close) and do not let the homeowner know all the options available to them (modifications/ bankruptcy), they are out to solely benefit in their behalf which in itself is predatory

People are more cooperative when they have options.

Owner financing could indeed be a viable option given your good relationship with the owner and the favorable mortgage terms.

You also have the option to refinance into a conventional loan as early as 6 months if the equity/LTV meets guidelines.

Another option as well is tapping into your referral network.

On top of this, our property management options also leave something to be desired.

I'm wondering if renting a 2-3 room apartment and setting it up as a midterm rental is a viable option to get started, or if it's just plain stupid.

Have you explored any bank statement loan options ? 

We have two options on ours and the owner can choose.