GARL revived as light rail.

Having been cancelled due to budget cuts in 2009, the Glasgow Airport Rail Link looks set to be revived, but this time as a light railway: http://www.bbc.co.uk/news/uk-scotland-glasgow-west-34931594?post_id=10153291660636131_10153616287831131#_=_
I have several questions regarding the development:

1. Will the "tram-train" be entirely grade separated, or will there be street-running?
2. If there is street running, what will power the trains? 25kV AC is not really suitable for street running, so will it be battery-electric, dual voltage, diesel or even a Parry People Mover-style flywheel system?
3. Will there be provision for freight (ie. Aviation fuel) to use the line? Prestwick airport gets its fuel by train. It makes sense for Glasgow to do the same.

I also hope there is an interchange at paisley Gilmour Street to serve passengers from Ayrshire. It would make no sense to have to go all the way into Glasgow Central to catch the train back out through Paisley again to get to the airport.
Edit: RailQwest are urging that GARL should be completed as heavy rail and not light rail. I fully agree with and support this stance.