This relative will be handling most of his estate issues moving forward.

Partner #1 will be the financier and provide the funds to purchase and will handle the tenant payments, while partner #2 will manage the rehab of the property and ongoing maintenance.

They also have a live call center that can handle the inquiries with a live person. 

A property manager will cost 10% of $2,000 monthly rent or $2,400 a year, possibly less.Do yourself a favor and find a good, quality PM to handle this for you.

He's been fairly responsive on a few matters (removed a tree with several dead limbs hanging over the yard and house), but I'm a little worried that he's not sure how to handle mold and/or problems with pin-hole leaks in copper plumbing. 

If that's all they do I can handle that with just the tips from the book.

One company owns everything and does nothing (this is your SLLC a/k/a "asset holding company") and a completely separate company handles all of your operations (this is a traditional LLC a/k/a "operating company") For the operating company which serves as your face to the world and through which you do all your business, you establish a Traditional LLC to carry out the operations of your investments.

The 20 belong to another company but we will be managing it for them.

The "former" tenant is not responding to calls or text messages for the last week.I have never dealt with this as I have typically bought properties empty, or tenants have negotiated in good-faith for an exit, and paid appropriately.How do I handled this because I wish to start renovations.

Then got in contact with the law firm who actually handled the foreclosure case.