Sending you a dm to connect! 

Would it be worth it to rehab if we sell it or rent it?

A quick Internet search of "Costa Rica Mortgage Loans" turned up a couple of brokers and private equity offerings.You could also try to get the seller to finance part of the purchase price.Or borrow it from your 401K, if you have one.Depending on your credit score, it might also be worth looking at rates from a local credit union, bank, or even Prosper or Lending Club for a personal loan rather than a real-estate secured loan.

I think it is better to connect with many GCs, find the ones you want to work with the most, and have them walk properties and provide bids for you.

How important is finding a mentor in this field, and what is the best way to connect with experienced professionals who can provide guidance and support?

I want to take this as seriously as possible so in my case, is this worth it, or is paying for a coach/mentor unnecessary? 

If it hasn't been too long maybe it's worth try selling again.In terms of cash out refinance, most investors would do a 70-75% cash out refinance given it debt covers.

Many of the most successful (read as: founders that are worth well into the 9 figures, have survived multiple market cycles, etc) syndicators I know started by working in real estate for other companies.  

Perhaps it's worth it for the increased appreciation you anticipate.

Would love to connect?