Overall, an investigation into what constitutes 'normal wear and tear' is the most prudent course of action.

I think the main quibble someone would have with the above is that capital invested with a reasonable expectation of a passive return constitutes offering of a security, not a syndicaiton.

In my opinion, a duplex constitutes two distinct dwelling units, and consequently the restrictions imposed by this section do not apply. 

I have no issue with this since it would cost me more to have it professionally done.I just want to make sure this arrangement is recorded as part of the lease in an addendum so that there is no confusion as far as what the tenant is responsible for, what the I as the landlord is responsible for, what constitutes a failure to meet the standards, and grounds for ending the arrangement an discount to the rent.Does anyone have a sample of one such or similar addendum I could use as reference?

Failure to do so constitutes a violation of that contract. 

HAThe town bylaws state 5+ occupancy constitutes a  rooming house, and I don't want the town to slap me with a bunch of fines or otherwise try to stop me from cashflowing!

Most states have requirements on what constitutes a bedroom.

What constitute good opportunities will depend on your investment goal and time horizon (wealth building?

Does this constitute a change in relationship, and should the owners be giving the brokers/managers pushback on this?

After you know your why, work backwards to establish short-term and long-term goals to help you accomplish your why.Understand what to you constitutes a great deal.