Coming from a tech background, airbnb platform is well designed and works smoothly, compared to the old/ugly VRBO at the time (not that much different today, hahaha).

PenFed Credit Union made the financing process smooth and straightforward, and I'm grateful for their assistance in making this investment possible.

What have other investors done to ensure the seller follows through with repairs and closing goes smoothly?

It is unfortunate, but it does happen and when things are not going smoothly that is where we earn our reputation. 

I have made one investment in Thailand last year and that went very smooth however, I would like to be able to get legal advice, contract review, etc related to future purchases as an individual and through my Solo 401K. 

The big banks all say no but we found a small local bank who funded it no problem.The process was actually so smooth we did 2 HELOC’s last year with them back-back.

Two doors and things are moving smoothly.

Next guy slides a napkin over it and hides it.

The sellers do not like to wait that long to get their funding (they could have sold it to someone else and got their money nearly immediately) so they aren't thrilled when they find out that your SDIRA is through Equity.On the plus side, Evantage (online account management) makes it fairly simple to pay bills associated with your account so once the deal is funded, it is smooth sailing.

To ensure a smooth transaction, they just open escrow with their preferred title company/attorney's office.