1) You need either a Nexus or Alfine shifter. No others will work correctly.
2) Stick on what you like, You can run it with a double or triple up front if you want.
3) Mine spent the Winter being abused by me and the rim broke not the hub. I had the hub serviced as the rim was replaced and all was well. A clean and reassembly was all that was required.
I really like mine. I’ve got one on a Cove Stiffee. The gears are high (I run a 34T) for the steep stuff but you just MTFU and ride the gear you’ve got. You do need to learn to change gear earlier though. It doesn’t change down under load (like you can do in a normal set up) so you need to shift early.
Some people can adapt to that, some can’t. IMO, it’s no different to adapting to ride a FS compared to riding a HT or rigid.
They are heavy though and it does pull the back of the bike down. Also the bolt-in axle is very stiff and tightens up the rear end loads. I’m running 426 coil Pikes up front which has balanced the bike nicely – it’s now heavy front and back!
It was great during the Winter and following a strip down it’s almost ready to roll again. Will be riding it during the Summer as the OH has started riding and the Hustler is a bit overkill to potter around the bridleways on.