I know this is all part of a glorious thread revival, but I'm going to reply anyway.
Now the Nitros, they have caught my eye in the past, but I haven't had a chance to demo one yet. I will keep them in mind.
Not that my shitty beginner-intermediate word weighs anywhere near as much as those of the more advanced riders here, but I'd still like to +1 the Nitro Team GW. I rode a 159W for three days in Val Thorens this winter and I loved it.
Of all the boards I've tried so far (9) it definitely has the fastest base. In fact, the base is so fast it's ridiculous. The board just doesn't want to go slow. And by fast I mean the way it accelerates - I'm not talking bout how stable it is at speed. Yes, that depends on the wax job but seeing as I tried 3 different newly waxed boards from the same shop I'd say the difference was quite established.
I didn't encounter icy conditions during those days but I'd say it held an edge as well or better as any other board I've tried, and we were practicing hard, drawn out carves on it. A few times when I fucked up and caught an edge it would take bite out of the hardpack the size of my head... Methinks it's a sign of good edge pressure.
The way I remember it the Skate Banana 159w I tried was heavier and bulkier that the Team GW 159w.
Definitely worth checking out, I hope you get to demo it. It definitely fullfills your prerequisites b)-f). You'll have to test a) for yourself, but I know BA thinks it rails.