From the great comments to date, I may have to rethink this idea a tad. I see that most aspects have been covered in some way or another.
Whatever you come up with, you have to remember that phone numbers have country code. If you are going to post any more phone numbers in the format without country code eg. (1)(503)580-3900; +1.503.580-3900; etc. I reserve the right to tease you mercilessly.
You are correct, 2112, but I was just showing examples for example sake. If by chance such a site were built, and phone numbers were to become part of vanity addresses, that concern would most likely be addressed.
As far as for the length of a vanity address being maxed at 40(?), the other extreme could easily be 5(?).
Imagine the following BVAs:BadBear
demonoid
eurovps
Or just a full name:TerryWright
BobFoote
BeckyLong
EricVonSustern
Hell, an actual domain name could be the BVA:kens5.com
coachella.com
primitiveshoes.com
crazyforcows.com
bayliner.com
nrafoundation.org