Re: one handed spey casting
Once you have learned the moves Spey casting (should be Ness casting BTW) is just a solution to whatever problem you have. The first is generally no backcast room but it can also be a strong upstream/downstream wind or just that you have a big/heavy fly. My most common move is a Circle C to get the flies and line upstream to set up a roll or jump roll. In a strong upstream/downstream wind this is a vital tool and very easy. I have been trying to perfect my turbo roll but it isn't there yet. I have found that sidecasting the roll helps cutting through the wind as well. Already Wyoming is modifying my casting! I have found that my left hand does follow the handle in a 2 hand shape though.
The longer the rod the better IMHO.