About the suggestions regarding fastmove:
Currently, none of those are possible, simply because gridmove isn't aware of where the window is. I mean, it only moves the window to a grid, and doesn't keep track of which windows are in which grids. It's not impossible to implement your suggestions, only something i can't do right now.
About having the windows move to the other screen... You can make your own gird, which could have for example in monitor 1, an element that would move the window to monitor 2, and in mornitor 2 would have an element that would move to monitor 1.
ps: I have attached to this post, another version of axcrusik's grid, which allows you to, in conjuntion with being able to move windows with the numpad, move them in a way that makes more sense.
To install it, just add it to the "grids" folder of gridmove, and replace the earlier version.
Another interesting feature is that now you can add a modifier to reach for numbers higher than 10 faster. Check on the ini file, and set the key FastMoveMeta like this:
That will allow you to move a window to area 11 by pressing win+\ followed by 1 (instead of 11 like when you press win+g).