If you're talking a house flip, I could be either of the two parties, based on my experience and funding ability. 

I'm from Slovakia and live in Czech Republic (Prague is the Capital)I decided that I want to make real estate business big because it is a beautiful business that brings value to all parties.

Once all parties have signed it’s a done deal.

The hard part is neither of us are in a position to be in the area and touring the properties, we're long distance at this point so we're relying on our agent.

I ise 3rd party sites like zillow most of the time 

Are you putting it under contract and marketing it or bringing 2 parties together for a profit?  

For example I know in many “flips” an investor invests 100% of the money and the other party manages/completes the rehab and then each party splits the profit.

If you have not met or worked with them before, I would consider at least checking the place out in person (plane ticket is a lot cheaper than some crazy headaches) or making sure you have thrid party inspector and a lot of videos.

Assuming the lease says he can use the parking space(s) and the iif the seller is unwilling to deal with the third floor tenant (and unless you have addressed this in the P&S she may not be interesteding in doing anything at this point) then you will have to once you own the property.

With a requirement that all this documentation be reviewed by a third party, adding to the costs of the project.