unfortunately toll free numbers are not able to be ported and the reason is we are not able to support those kinds of numbers. You ARE able to change a cell phone to this service as long as you still have one cell phone acting as a cell phone on your plan. there are a couple of qualifying things you do need to have.
1. A Rate Plan of 39.99 or higher for individual.
2. a rate plan of 49.99 or higher for family time pooling plans.
3. A High speed internet connection (cable/DSL)
4. The Hiport router
5. A touch tone phone
6. ONLY EXCLUSIVE TO TMOBILE CUSTOMERS.
as for the port forwarding it depends on which ports need to be opened for which programs/ software. i have my router set up to do port forwarding. i specified the pors on which the programs used and on which IP. it works great.
in the event that the internet goes down. so does you phone service. do not worry though. the Vmail will still work and you will be able to retrieve you messages.
It is def. a mst have to save money. i currently have had the service since a week after it launched only cause it took them forever to ship me my router. i have also bought the phones as well. i'm not sure if you looked into researching it but with the ten dollars you get UNL NW calling, Call waiting, call forwarding, Caller ID, Vmail all for that $10.
I hope this answered a lot of your questions.