sounds like fun in the electrical department HEHE :tumbsup:
oh and i wouldn't worry about the noise of the chain over the rollers being a pain on longer rides as it will never have any longer rides, you will forever be fettling!
i assume the air con fan and radio and aux mp3 socket are all in the post then? did it pass the MOT and have you got the registration plate sorted?! HAHA
on a more serious note though, all sounds pretty cool and the most technically advanced bike i have heard on yet. surprised you haven't invented the 'stuee electronic shifting system'
as for your free wheel, i assume you know the difference between free wheel and free hub? and as you said free wheel i assume that is what you have as they are not to be mistaken. if it is free wheel then just get special tool for your free wheel and unscrew and purchase and fit a new 7 speed free wheel, that way you get to keep the derrailer, cabling and shifter, this is assuming you are happy with 7 speed and don't want to change?
Cheers Ed