I use a combination of mouse and keyboard for moving -- if I'm trying to target something while moving, just hold W to keep moving, and click the target. If I'm trying to hit a skill keybind while moving, use mousekey for autorun or click both mouse buttons to keep moving and hit the key.
As for the nostromo, I tried it, and couldn't get used to it. It just didn't have enough buttons available unless I remapped the keys to remove movement from the keys themselves, and the crosspad was horrible for me to try moving with. Mouse-only movement just hasn't been intuitive for me at all, and very unsuccessful as well. I reverted to my keyboard and am still breaking myself of clicking, though getting much better about it.
Don't worry about moving with your mouse and such. Just know how to do it for that moment you need it and use the Blizzard keybinds. There is no reason to have to switch around your keybinds. The GCD is so long that a split second on hitting a spell doesn't matter, and if you know how to move the mouse to turn, you can when you need it.