Can I use a double chainring with an Alfine hub?
If you use a chain tensioner (or rear mech!) with enough capacity to handle the difference in chain length, then yes. We haven’t tried it but reckon the Alfine chain tensioners will probably be OK for a 24T/32T double chainring. Triple chainrings will probably mess up your chainline a bit.
Yep, look like you can (double that is);
Can't wait to get the 11spd Alfine for the F.U.