Is this legal in Baltimore county?  

I would also seek legal counsel in the same area where your property is to find out how you can minimize your fines.

However, as a licensed agent, I legally can only do the deal as myself, an individual, not acting as an agent to anyone; self-representing.  

In either case for what I'm doing, I need an architect for the site plan for the change of use and a land use attorney for the legal aspects and complying with the notifications to the surrounding property owners. 

Purchase the lease from the Wisconsin Legal Blank website.

You should also investigate if there have been changes in laws or zoning that the current property is grandfathered into that would pose restrictions on a new construction.  

There is a plethora of vendors available who handle title, site visits, loss mitigation, legal/foreclosure, property preservation and property sales -- all can be directed via phone/email. 

You can not legally, for tax purposes, be landlord and tenant.

It was rehabbed then and the basement was also redone and he added 2 legal bedrooms down there.So the issues I'm having is how the heck do I comp this type of property?

Besides the legal notice and opening bid.