Short answer to most of your questions:
I just don't think many people are using isapi-wsgi. It has it's
own mailing list here:
https://groups.google.com/forum/#!forum/isapi_wsgi-dev
And you will note there are only six posts since 2012. We are
using it in a production environment but only on Python 2.7.
So, specific answers to your questions:
1) Given the minimal traffic on the dev list and few recent
commits (
https://code.google.com/p/isapi-wsgi/source/list) its
likely that the project is stagnant.
2) The cryptic hard-to-troubleshoot error messages always plagued
me. There are some docs somewhere about using pywin32 and "trace"
to enable debugging of isapi-wsgi. I don't remember ever getting
that to work well. That is why I created ISAPIWSGIHelper, so that
the error messages were caught and handled properly.
Hope it helps...If I as you I would not be trying to get it to
work with Python 3.4 unless I could get someone else to confirm it
should work there. If I had to work with IIS I would either A)
stick with Python 2.7 or B) setup an HTTP proxy to something else
serving the WSGI app.
HTH.
Randy Syring
Husband | Father | Redeemed Sinner
"For what does it profit a man to gain the whole world
and forfeit his soul?" (Mark 8:36 ESV)