I can agree on the mailing, I will discuss your remarks with the other developers. We are trying to support also other "community platforms", so we have now a forum:

http://forum.texmacs.cn

a Gitter room:

https://gitter.im/texmacs/Lobby

and a GitHub mirror here:

https://github.com/texmacs/texmacs

where you can post PR. As for Bugs we prefer the savannah bug tracker but if you post something on GitHub we will take it in consideration too.