Not to discourage you (if I haven't already) but this would not be the ideal place from which to manage a first project remotely.  

Don't put more time into until they are ready.Build that last little bit of rapport by saying something along the lines of "I would like you to find the best deal possible and it sounds as though mine is not as ideal for your situation as some of the other offers you have received.

Lack of fund investors like me will start at an affordable area to learn about RE along with building experience and slowly crawl back into the ideal area in the future. : )Hope these answer your questions.

They buyers would ideally like to work with the recycling company to recycle as much as possible. 

In fact, that may be the ideal situation.That being said, I echo @Steve Vaughan, you are willing to put in detailed effort. 

(that's good)Now, in late December I sent them a letter telling them that I'd like for them to send the net 6 month check a little sooner than February 1 (ideally 2 weeks) because that's how long it took to clear my bank.I got no response from the letter.

The percentage of my net worth invested in investment properties is slightly higher than what I consider ideal. 

Ideally your tenants want to be left in peace, pay their rent on time, want to know how you'll maintain the property, and also discover that you're not a pushover and can't walk all over you, so keep that in mind when you're drafting this communication. 

After talking with a few lenders they told me that since I have an ideal credit score that they will work with me on securing future rentals (and can offer additional loans beyond that).

Cons - Needs a lot of work, highest up front cost2nd - Typical duplex, Worst cash flow3rd - Minor fixer upper duplex, Pros - lowest up front cost, better cash flow than typical, cons - not the best neighborhood, not ideal layout (all common walls shared).Well, that was a mouthful.