I signed up today just to commend you on your work with this
I'm not yet on BT's FTTP, but that's only because I was yet to find a solution to being able to use their Digital Voice service (via the SH2), but using my own router for 'normal' traffic (Linksys WRT1900ACS - running OpenWRT).
Your post gives me hope that it is possible, even if I haven't yet worked out what each bit is!
I'm sure there will be more guides / helpful posts when more users get online with FTTP.
We've recently had to change landline numbers (long, boring story) and my other half is insistent that it doesn't happen again any time soon (I'm still looking at a number port to a proper VOIP solution).