I’m very bullish on Passive Investing and creating multiple streams of income (mailbox money as some would say) and see this route as an effective way to achieve that. 

I’m contacted multiple times a week by individuals who buy lousy real estate in Philly and I hear “ but the agent told me” or “the wholesaler promised me” it was a legal use…the rents would increase…..I could rent this section 8 and achieve xyz rent etc. etc.  

If I HAD to pick one of your 3 options, I'd probably go with option 3 because it's likely the one that you can achieve the quickest... especially if you aren't concerned with cash flow. 

Do further research on your target acquisition.  

Leverage Market DataUse data-driven approaches to adjust your offer strategy: Comparative Market Analysis (CMA): Constantly analyze comparable properties in your target area to understand market trends, price points, and days on market.

Of course, this is just my opinion but I bet I'm not alone..If I'm an investor, I think the returns you're able to achieve in Costa Rica are higher than normal because you focus on these large properties and, as @Martin D. mentioned, prices in that country are too high and returns too low.

If the garage isn’t being used, turning it into a dedicated game room should add some value particularly if you are targeting families or larger parties.

The last big name that I knew that went up to 80% on anything was CIVIC and they are not doing new loans as of last week. 75% is seemingly a good target on a cash out refi for a DSCR loan, assuming credit is good and the property cash flows well. 

You have to determine what your goals are and then attempt to achieve them.

We reach agreement in principle with the seller on what we mutually want to achieve.