One more tip – people remember stories that trigger their emotions.

That said, there other practical considerations with the victim tenant in situation, meaning, maybe it's a "lesser evil" decision to allow the victim tenant to terminate early without penalty based on the circumstances.

Another consideration is to get a portfolio loan that will take on both properties at an average rate which will give you capital through a finance (refi similar).

1) What are legal considerations that I need to include in lease agreement?

Other consideration that we've found critical is housekeeping and local handyman. 

In most places, like Benjamin already mentioned, STRs and MTRs have different legal requirements and considerations.

You raise some great considerations here.

I created a free guide for beginning real estate investors with an overview of the critical considerations for starting out.

If there was a Fire, Windstorm, Etc. that is covered by the policy and it results in a loss of Rental income, that coverage would be triggered. 

I have explored this idea in the Caribbean and South America a few times and never pulled the trigger as it was too much headache.