.- Im thinking of not charging security deposit because of all the strict MA laws and just using the last months rent as a sort of security deposit, thoughts?

They also have strict rules for renters about sharing the kitchen, cleaning, etc. with monetary penalties for not complying. 

It seems like it is more at the behest of the hotel industry and the few permit holders wanting to protect their captured audience, because they strictly disallow hosted STRs, whether that be an ADU, extra room etc.

Evictions, resident's passing away, posting notices, doing preventative maintenance walk throughs, resident complaints, neighbor complaints, skips, move outs, turnovers, emergency maintenance, etc.I used to be strictly on the ownership side, from 2016-2020 I hired property managers.

Here are 2 articles talking about new regulations they're trying to put on STRs there, which definitely could impact your rental income, especially if you buy in an R-1 area. 

Compliance issues regarding local landlord regulations not an issue in my area.

Colorado is quickly becoming on par or maybe even worse than California as far as landlord/tenant regulations. 

In making this determination, the enforcement agency shall consult with the entity responsible for enforcement of building standards and other regulations of the State Fire Marshal pursuant to Section 13146.(4) The enforcement agency shall not approve any applications pursuant to this section on or after January 1, 2030.

@Belinda Fello- Usually, when you rent a property that has an HOA, you have a term in your lease that requires the tenant to comply with any rules or regulations of the HOA. 

A heavily regulated market.