As the tenants move out, you find a really good project manager or someone that can help you with light rehab some paint and carpet work while you use professionals for the heavy stuff like changing a water heater. 

If housing is unable to do anything, hire an attorney and get them out as soon as possible, period.As @Thomas S. pointed out, you should consider selling this home or giving it to a professional property manager that can get things back on track and put money in your pocket.

Which renovations do you leave for professionals?

Try to find a professional who can help youGino

Thank you everyone for your replies - it all sounds like solid advice:I understand to the professional real-estate investor this might sound like a nauseatingly safe strategy but I am a novice and admittedly would like to play safe while I learn the ins-and-outs of the industry, being a landlord, maintenance, renovation, regulations etc...

I came here for professional advice from like minded professional people who wish to help propel my success the way I wish to help propel theirs.

I should be able to get it down to 10% of rents collected with a professional management company; however, I'm assuming since this is my first property there will be some headaches with coaching them how I'd like to approach ongoing communications, repairs, etc.

Check out "Real Estate Professionals of Metro West" and "Boston Real Estate Connection" on Meetup.com

Ideally, this would be the same person/professional that would be responsible for formulating and presenting a recommendation on your request to the Zoning Board. 

A fingerprint card may be obtained from the Department of Business and Professional Regulation by contacting the Customer Contact Center at (BP won't allow me to post the tel#- I'll message to you).