If Crawlspace make sure low point drain is working properly.   

I would like to know if there is a method to properly and fairly analyze the correct offer for a cash deal.

You should do lots of research and drive by each property that you might bid on.It depends on the laws in your state as to how string your tax deed is.I have been very luck and now have a nice portfolio of tax deed houses.I am also currently litigating a tax deed property where the precious owner is trying to over turn the county issued deed.With proper research you can mitigate a lot of the risk.There is  lot of information on the BP forums that you can study on tax liens.

What is proper etiquette?

We wouldn't be able to advertise as a "property manager" without being properly licensed.

How do I go about getting the proper paperwork( documents) for a beginner in whole sale.

They usually want a buyer broker on the other end guiding the buyer through the process and knowing things are handled properly.

If you stumbled upon an amazing property by luck to sell that might work but often wholesalers are selling overpriced junk because they do not know how to properly underwrite commercial assets.

Maybe I’m not doing the math properly? 

No, not unless she and the buyer are contractually bound, which then means the business relationship has been papered properly and she is allowed to negotiate on behalf of and represent the buyer.