The name of the game these days is having amazing design and amenities to stand out from the competition. 

and then use the bulk of your proceeds to purchase the second house with less debt that is higher interest.It's a juggling game. 

Foundations are designed to support homes, not hold back water (maybe to some small degree).

As the saying goes, the best time to buy real estate was 20 years ago, and the next best time is now… but with these interests rates I’m curious if it makes sense buying and then if they drop later refinancing to the lower rate, or just hold off purchasing until the rates (hopefully) come down a bit.

Can play the game in the past, you must look forward.

Sounds like you have a solid plan, we are looking to buy and hold in Spain in the next year, fingers crossed!

For buy and holds, multi-families, retail, MHPs, etc., you would use something else.

Decide which game you want to play.

Obviously, the slab is still holding everything it needs, so the dirt would just be to keep it that way.

Your holding costs are going to kill your numbers.