My business partner owns a roofing company but has weak credit and more limited cash flow.An LLC is a common choice for partnerships since it protects personal assets and simplifies tax management.

There are risks too, when buying condemned and burned-out houses because you may not be able to control the environment where these properties exist.

Nore the rent control bullet is CA specific and I do not know how ADUs affect rent control in other jurisdictions. 

I wish I had control over how far in advance the calendar was open, but that is up to the PM. 

What are some considerations in finding a provider that offers checkbook control?

Control of overall project staying diligent.

Many times they do not realize the adding of the adu makes their existing unit rent controlled.  

In the latter I would much rather have my money and be in control. 

Losing control of the process matters. 

When I went to cancel my membership, RentRedi gives you a large box in which you can describe to them why you decided to cancel, and there was a SHORT and hidden character limit!