Following David Green's Core 4 strategy (realtor, contractor, property manager, and lender) gives confidence to invest anywhere.

2) And what point is a property manager worthwhile?

I have clients right now operating in the black and they are doing it because they are aligned with a great team for management @Alice Horn and they purchased with a clear plan to move forward. 

Combining my experience as a guest in cabins with some knowledge as a manager of a few houses with them:1 - Patio. 

My plan would be to actively manage the new property and hire a property management company to manage the first property. 

With higher interest rate and negative cash flow currently i won't be able to hire property management and planning to rent it out myself.

The SDIRA can own an LLC that you're the manager of giving you checkbook control allowing you to invest in as quickly as you can write a check or do a wire transfer.   

However, given my circumstances, I will not be able to manage STR on my own.

Our lake home we have has not been used as rental income per-say, only a few times, but were looking into that now with a management company.

If you can cash flow, and are able to find third party management, it may be a deal.