Then, after they have moved out and returned possession of the unit to us, we calculate "pre-paid rent" for the days following the actual date they vacated the unit and it becomes a credit on their account.

They will also look at your real estate resume, they will vet your property manager, require one year prepaid insurance, and ask for every possible document from the sellers!  

If the landlord properly raised your rent to $550 while you were living in the rental unit, you can expect to owe the landlord $50 for rent during the last month of your tenancy (that is, the current rent [$550] minus the prepaid amount [$500] equals $50 owed).If your rental agreement calls your entire up front payment a "security deposit" and does not label any part of it "last month's rent," or "security for last month's rent," then you will have to pay the last month's rent when it comes due.

So I been talking to banks about setting up separate debit cards for my PMs, I would be able to filter one of them out online, but would not be able to tell what job # the charge is for.

I told him he needed to get to the nearest Western Union and purchase $2,000 worth of reloadable debit cards (10 in the amount of $200). 

Other components of the total deal cost would be the purchase price, estimated rehab, and any closing costs associated with the hard money loan (points, pre-paid interest, insurance, inspection[s], survey, appraisal, etc.).

Regarding the bank account number it is reasonable for them to want that for auto debits of payments.

What was some of your strategies used to reduce your own personal debit.

For example do I estimate 29 days of prepaid interest, or 4?

Whatever you choose, I would choose something that doesn't involve personal contact because that's when they are most likely to hit you up with stories about Grandma's heart operation or that someone stole their debit card.