This would give you time to make sure you can get all the parcels under contract and also work toward approvals without spending a whole lot of money only to get denied or have the last seller hold out for an unreasonable asking price. 

If the rep feels your request are unreasonable then it's good to know that now and look at someone else who can get it done.Make sure you tell the leasing rep how often you want to be communicated with for marketing efforts and steps completed.

Is it unreasonable to say they cant have that in the back yard, I did said say they can have access to the back yard but didn't expect them to "take it over"...

The repayment term of 18 to 24 months seems unreasonable without details to support it.  

I have a deal in process that I can still walk away from and I'm hoping someone can help me validate whether this is a reasonable or unreasonable purchase.

@Derek Lacy the FAIR plan rate does not seem unreasonable ($687/yr for a $100K house).

This seems unreasonable.

Quote from @Christopher Davis: i would say you're being unreasonable.

It's a cheap part and not a difficult repair, but you have to pay for their time, and it's not uncommon or unreasonable for PMs to have minimum trip fees.

I don't ask them or invite a negotiation, but I don't become unreasonable either.