It's really important to know that people giving advice here do not know the specifics of your situation.

I became a realtor specifically to help other investors in the area here :) The property is LTR - Myrtle Beach is growing so fast that it has LTR opportunities.

There is really no IRS private letter ruling specific to DST (or at least it is never mentioned as such) as far as I can tell, despite some advertising to the contrary.

The three most used “exemptions” are (1) the general exemption for private funding (2) Safe harbor Regulation D (either 504, 505, or 506 B or C),and (3) crowdfunding specific regulations.  

I don't know where to look to find the answer to this specific situation: I have partners with an inherited home.

As already mentioned it definitely depends the specific scenario! 

Specifically:- Are there any exceptions or tax treaties that could eliminate or reduce my US tax burden on foreign rental income that is otherwise taxed locally?

Capex's budget is $2.2MM.

At this point I am thinking to ask my lawyer to threaten with the specific performance lawsuit if she doesn't want to close in the first week of March.

In order to do this you need to know what's going on in the area of your rentals, consider your exclusive contractor relationships, and get someone to run a viable cost estimation on your property (specifically an "insurance" cost estimation).