As others have indicated it is acceptable to make an offer based on what is known and then during the contingency/diligence phase if you find out something material that makes the RE worth less you can either make a lower offer, ideally presenting the rationale, or pull out. 

Unsure of the legal expectations of the easement and what you are or are not entitled to, but I would try to work amicably with the owner since it will probably come up again in the future, whatever happens, I would send him a thank you card and a little present when it is all over to smooth over the next issues for when it arises.Just how I would handle it.

There is always some sort of presentation and is free.

This presents an issue as I'm not sure that I can place my lender in a first position lien without title to the property.

Be wary of people who are ‘experts’ at presentation but who haven’t done a deal in years3) Set some objectives for what you want from the mentor4) Don’t limit yourself to just one5) Force yourself to do work before you bring a mentor on board.Good luck!

My suspicion is it may be more of a break-even at best type scenario for the first several years due to vacancy/tenant issues and especially deferred maintenance/capex expenses and management costs. 

And sign it with them present.

He / she may like the monthly check paid on the seller carry back note instead, deferring capital gains.

All bets are off in the retail space right now and if you loose a tenant like a Walgreens or CVS or restaurant they can be difficult to fill and expensive to upfit for a new tenant.How do you manage the environmental/biohazard risk that such a use may present?

If you build a track record of wholesaling and hustling I think you could present yourself as a good candidate to the right group.