The 3 activities that you listed might all count, depending on the circumstances, but none is automatic, with selling the property being the safest of the 3.

To keep it simple if you have good credit and a decent amount of assets this will depend on your market on the amount needed but try to always have access to a good amount.

However, the choice of location significantly depends on your investment strategy.

Hard to say right off the bat which is a better option since it depends a lot on what you are looking for and your situation but speaking with a lender that understands the application of primary residence loans in multifamily will be important to help you find the right option.

This is a complicated question because it depends on a few factors:1.

Tulum is so dependent on tourism.

Your success will depend on buying appropriate investments for the local market. 

The amount of tax you'll pay will depend entirely on what the adjusted basis of your sold mobile home is at the time of sale vs. the net sales price. 

You can also find good investment opportunities in your local area, and as many others have mentioned, your success may depend on the people you know.

Insurance could be a problem depending on the flood zone.