"Now, one year later, we have discovered that the past and current
owners never formed any kind of an owners association, and that the
building was, for a time, self-managed before those responsibilites
were put in the hands of a property management company. "

This is virtually impossible. If this building is in fact a
condominium, then part of the legal documents necessary to establish
and record the title must include a Master Deed and Bylaws. Those
documents must be recorded with the deed and also filed with the Dept
of Community Affairs for the state of NJ. And those documents
establish the association which consists of all the unit owners,
describe rights of unit owners, obligations of the association for
common area maintenance, the procedure for voting, electing trustees,
officers, etc. You said you now have a President and you are
Treasurer. How could you have held an election without having an
association? Did you follow the rules in the Master Deed and Bylaws
for a valid election?

What you need to do is read the Master Deed and Bylaws and find out the
requirements for annual meetings, elections, etc. Find out what the
responsibilities of the Board of Trustees are. Make sure meetings
are held with correct notice to all unit owners. Join the NJ
Community Association Institute, which is a non-profit organization
that advocates for NJ condo associations and is a good source of
educational information and the laterst condo issues facing NJ.

IMO, if this property consists of 9 units, you have the worst of
everything. It's not large enough to have any leverage or economy of
scale in getting maintenance done. But it has much of the overhead in
the form of management oversight that would go with a condo that has
100+ units. Apparently, you are now realizing this for the first time.

I would not get all in a huff about whether the management company
might have not followed the ByLaws correctly or paid out some claim for
a leak incorrectly. If the lead happened from one owners unit to
another, it would sound to me like that should have been handled by the
insurance companies for the two unit owners, with the one causing the
leak having to pay. But if it's water under the bridge, it's probably
more important to figure out what the hell is going on and getting a
board of trustees to over see what the management company is doing. I
was President of an association for many years and issues like the
satellite dish and payment for damage from water would never have
occurred without the board having known about it. Also, no bills were
ever paid without the signatures of the Pres and Treasurer, which was
done at our regular monthly meetings.