I have heard that onsite staff could also be the employee of the 3rd party property management company, but just wonder what is the normal practice?

., at least a x by y inches box in the top right corner left blank for use by the courthouse staff who will actually record the deed).Once you have a proper deed document, ready for the seller to sign, you'd need a way for them to sign it before you give them the money (again, with the correct number and typeof witnesses/notary).

They're saying we have to cover their staff expenses for the rest of the year?

Most "travelers" (which is what hospitals call them) end up working the night shift because full time staff get the more choice day shifts.

Is there so much available it can be overwhelming? 

Once you have approximately 100 units, managing them becomes more convenient with a combination of in-house staff and external maintenance.

Starting on your own (despite your extensive experience with your family rentals) can be an overwhelming task. 

Even though it seems overwhelming, take the plunge and make your first investment.

What makes me hesitated is just the same as what @DongHui Patel said, they will pawned you off to some junior staff.   

His staff is great and everyone is real tight.