Like seriously, with as much due respect as I can provide to you in this situation, you guys need to evaluate what you actually do instead of what you think you’re doing.

They will evaluate the property, eventual costs with repairs, etc - depending on the service you asks and their fees are about 250 EUR per report.

If you don't know how to evaluate whether or not it is a viable investment, why would you make an offer?

Evaluate forming an LLC to protect both parties and outline everything in an operating agreement.

Real estate's "gross rent multiplier" is Wall Street's "sales to revenue",  "cap rate" is roughly "P/E ratio".When evaluating markets and investments I tend to start with GRM (or lazily the 1% rule), then attempt to return a cap rate based on assumptions about costs, then I work my way to multiple years of projections (assumptions about inflation, amortization, tax benefits, etc), and if I am partnering with one of my smart friends I have to pull up an IRR (internal rate of return).I also look at regional employment levels, median income to rent ratio in the zip code etc. 

Some lenders might evaluate the same deal differently.

Evaluating deals on this site will help you understand expenses, income, and financial statement.

Learn how to evaluate a market by either reading and listening to a lot of content or by providing some sort of value to someone who already has that knowledge.

To determine the quality of a property requires to evaluate all of its return as well as potential return.  

I think it will prove to be especially important as I evaluate possible properties in the future.