OK I'll have a go.
1) Don't know. IIRC the spec says 115V. Seems like they don't see an international market for the 770. You may need a transformer. Talk to Tormach.
2) Milling without flood coolant isn't a problem. Mist coolant is a good compromise.
3) If you run 20 hour 3D profiling programs then get the auto-oiler. Manual oiling for normal operation is more than adequate. You need to pull the handle once every 4 hours.
4) A touch screen is not even remotely necessary.
5) Mach3 is easily the default controller. If you don't know if you need EMC2 then you don't need EMC2.