As of right now, the two are branded totally separate and have separate names.

I'm all separate so tenants pay.  

Wants and needs with seller's are two totally separate things.

Generally speaking, I'd keep your biz and personal account separate.

She also said I could take regular listings and wholesale under my corporate name, just keep them separate.

Luckily I broke out my responses in separate paragraphs so it can be followed reasonably well.

I have a separate checking account just for this purpose works fine and best of all it's instant!

I plan to make each unit a separate entity (I believe Quickbooks calls them classes) in the software for tracking rent and expenses per unit.But should I also report on them for tax purposes as 9 separate units or should I roll them up into 4 because that's how many separate addresses there are or should I roll everything into 1 property on the schedule C come tax time because it's one physical building with one mortgage, etc.?

2) With my lease options I offered before, it was basically a normal lease agreement with a separate contract for the lease option. 

You can do a standard lease and have a separate option to purchase agreement and don't reference the option in the lease, you can reference the lease in the option.