This makes for changes in the underlying ground over time affecting the foundation.

A town home wont have a unit above or below - the unit is owned from the ground or lot up to the sky.Multifamily units are almost always going to be zoned as multi unit with the whole structure being one owner, tax id, etc.

Focus on the market research throughout the summer, save more cash, and hit the ground running in the winter when better deals come around.

Here is the thing, houses don't just sprout out of the ground, they are built and have inputs to create them.

You do not have any grounds for an eviction unless the tenant is in violation of their lease contract.

I know it seems to good to be true though, haha Well then what I would say is build some reserves and get some ground underneath you before venturing into something that could wreck both your business and your relationship.

Quote from @Mackenzie Grate: I'm buy and hold.

That said, they are very popular, and gives the owner a valuable addition for your future guests to enjoy a pool when there is snow on the ground. 

I personally made a shift into two things. 1: Ground-up built-to-rent multifamily at a large scale 800+ units per build.

If it doesn't have a real in-ground pool/spa, don't buy a house in a residential neighborhood and expect it to do well.