All of the things you suggest are options to the beneficiaries. 

Similar to the comments above on using FurnishedFinder, also check Airbnb and sort for 30+ day rental options. in addition, I'd recommend talking to the local university and hospitals nearby by calling to their various departments.

It's best to reach out to multiple lenders to explore your options.

However for those that are still younger it’s a great option.

Whether it’s for startup costs, equipment, or marketing, leveraging your home’s value can help bring your entrepreneurial goals to life.Bottom LineWhether you’re thinking about selling, upgrading, or simply want to understand your options, your home equity is a powerful resource.

In Oceanside, New non-hosted STRs are prohibited outside of the Coastal Zone as of February 10, 2024.Most HOA's do not allow rentals less than 30 days so that is likely not an option unless you find a couple of places on the water that allow it but usually tough to find below $1M. 

Are you looking for "value add" options or turn-key?

Repurpose the money into a variety of different options.

However, currently there are no options for a foreigner to get a cash out refi on their property in Costa Rica other than for construction on the property itself.

With the limited info, I would say #1 is your smartest option but there are a lot of variables missing.