I also saw the option for the "announce-count" conference parameter (which i assume is what you're trying to use) and it didn't seem to work for me either.  I couldn't figure out whether I was doing something wrong or if it was not working - that's why I implemented it in JS.  Looking at the code now, do you have tts_engine and tts_voice defined in the conference config file.  Looks like conference_member_say won't do anything without those...

I can definitely attest to the confusion on your second point...  It took me a while to figure out the "default" conference controls as well.  As long as you name your caller-controls something else, it all works great.  The easy fix would be to modify the included conference config file so that the sample conference controls had a different name.  If someone removed them manually, it would work as advertised.

The wiki doc for mod_conference still needs some help too.  I tried to fill in what I knew recently by adding all the options I could find in the source and re-arranging the page to make it easier to understand for new folks.  I had to leave a bunch of ??? in places though because I didn't know what something did or meant...  Can anyone help complete that?