These answers may seem obvious to you all, but remember-- I've never done this before, so it feels like a huge unknown risk.

There were always a few unknowns hanging around but everyone was friendly, always offering me a shot or two of tequila, (readily accepted), and I would be on my way.

We have talked about taking out a HELOC, but then we are making payments on a home for an unknown amount of time for it to become rental ready.

But also very much discovered.Both places are not unknown to international tourism. 

Still waiting on an estimate from this contractor and meeting with one more this evening. on one hand, if it is in the budget, would it be smarter to lay the nicer things, but then the unknown of a bad renter tearing the house up makes me nervous.

Unknown to the seller.  

To which he politely says NO. 30 days would put us at June 30th, now he is asking if he can pay for partial of July.I dont really know the best way to navigate this.My thoughts:-Im hoping whatever weird thing thats going on is not as bad as I think it could be-I want them gone for the 1031/ ridding myself of this caliber property-legally they can stay till the end of July-possibly responding with "sorry we cant take partial payments"-not sure if thats legal or would come back to haunt me if he ends up agreeing and now im dealing with the unknown for longer

Lots of unknowns here, but this is the thought the process I use when analyzing opportunities. 

As an individual not comfortable with other people paying my bills I struggle to be an individual who might allow another person to take over payments and have the unknown idea of an unforseen even happening and my personal credit becoming ruined.Sellers in foreclosure typically have NO issue with me taking over their loan payments.

Duplication would be diving into research to find why those who struck gold did what they did, including going to an unknown patch of ground to make that gold strike.