> 3) originator collects replies and posts resolution or 
> further enquirers

Laudable goal; not gonna happen.  Hardly anyone who didn't learn in
ARPANet or Usenet days has ever _seen_
reply-to-me-I'll-post-a-summary-to-the-list, or other responsible
behaviors in a mailing list:  trimming replies, bottom-posting, et
cetera.  Doesn't make them/us bad people--just ones that have never seen
what "right" looks like.

> But, very unfortunately there are also members that cancel their
> subscription due to the high level of activity.

And the pages of HTML (like yours had, BTW--330 lines of it) and
quoted-printable crap that takes time to sort through to find the few
lines of text in messages?  My estimate is that wastes far more of my
time than multiple replies.

Replies direct to me, please; I'll summarize and post to the list.  :-)