In truth, I'm a mechanic that needed a building to work in. 

If they will allow the change, you'll need to submit proper drawings and plans and obtain permits for plumbing, electrical, mechanical (heating), and any other permits as required by your jurisdiction (often required to be done by licensed/insured contractors).Keep in mind you will need to change out your electric service panel to a 3-service entrance--1 meter for each apartment, 1 meter for 'common area'--exterior lights, etc. 

Learn the mechanics, pitfalls, upside.

Personally, it sounds like a lot more risk involving contractors, possible mechanic's liens, city permitting issues, insurance, etc.

Look at the mechanical systems.

I got full inspections on my first 4 properties, and then "mini" inspections (basically checking the plumbing, electrical and mechanicals) on the next few.After that, I started doing all my inspections myself (though I always use my project manager as an extra set of eyes).

He probably knew for some time that he was spiraling the drain, so was likely milking the cash flow while not paying the lender, not turning units as they became vacant, not servicing or replacing old mechanicals, etc., just as you suggested.

Based on tried and tested principles of hydrodynamic physics and mechanical and electrical engineering, ocean power technologies have been practices since long.

I'll like to spread my risk over residential, and commercial, with as many guarantees and safety mechanisms as are available, hence the need for a team.

Always work your REI into conversations no matter who your talking to, be it your priest, rabbi, doctor, auto mechanic, or anyone else.