As of March 2013, there is no way to adjust the number of rings it takes for voice mail on Home Phone Connect to pick up. It seems to be around four rings. In order to use a home answering machine instead of the default Home Phone Connect voice mail, one must set the answering machine to pick up sooner (like 2 rings).
Voice mail may be great for a true wireless (cell) phone, but many of us are using Verizon Wireless Home Phone Connect to REPLACE our wired home phone. We already have an answering machine that does not require us to dial *86 and listen to prompts just to get our messages. We just push the PLAY button.
I have recently learned that there IS a way to have the Home Phone Connect voice mail disabled, but we have to talk to the right person at Verizon Wireless.
Why not just put a link on our "My Verizon" web page so we can log in, and turn it off just as easy as blocking features or blocking calls or changing other features? That would solve many customers' problems with voice mail on Home Phone Connect.
I await comments and replies.
Although I don't remember what steps I took, I was able to use an answering machine on HPC during the 1.5 years I had it. As you have said, I very well may have called into CS to inquire about it when I first got it. If that was the case, I was able to have it taken care of without any problems. Regardless, I used an answering machine which picked up at 4 rings if there weren't previous messages and at 2 rings if there were previous messages.