The Asterisk-users mailing list is good, but it's best to post one question at a time.
(not send your whole system config in)..And also work on one problem at a time - for example, get your incoming calls working on the PSTN lines first.
Failing that, you could contact a company that does Asterisk support and pay them to get it all working!
The Cisco 7960 can be used with a hosted VoIP service. All you will need is to have each phone connected directly to a high speed internet connection. The Hosted solution will allow you to set up the system for either internal only or internal and external use.