Who subsidizes the loans, and is flipping homes, purchasing rental property, or other business-oriented activities a permissible use of the funds?

The owner gave you permission such as signing something turning possession over to you, or signing a lease with you.

(With legal/lease required advance notice.)I am reluctant to request permission to take strangers into their apartments when they are not home, in regard to their privacy and the liability for their possessions?

Others may be more permissive but I am in a anti-landlord state.

So to get dollars in your pocket faster, ask for permission to find ANY distressed sellers, then lock them under contract and work with the brothers to flip or wholesale the contract.

I have spoken to the neighbor already, who seemed fine with the work, but when I sent him the access form to his property to sign to give us permission he has no longer been responsive.

And do we risk anything by asking permission, i.e. if denied can we just wait out the remaining 8 months and do as we please?

I'm assuming I would need permission from the owner/property manager to do this.  

If the building dept also shows 5 units, you might want to just drop the issue, in case you ever want it to "become" a 5 unit, you've already got permission to do it. 

If you are not, then structure the lease to read that renovations/repairs can only be done with written permission on a project by project basis.