Nice images considering the wind.? I have a 12" F/4 Newt astrograph too and am currently working on getting the autoguiding under control.? Wind is definitely an issue, I had 1.5" RMS last time I tried.?
At F/4 you will need a good CC, I got the Paracorr 2 and have mounted it but haven't tried it yet.? Light pollution filters won't help much for galaxies since they are wide band objects.?
Have you tried using Gimp to remove the gradient?? The way it works is, you create a gradient in one layer to match what you see then subtract it from the image in another layer.? It takes sometime to get used to but for a free tool it's pretty good.
Hopefully you can take subs longer than 10 seconds.? For sure you've got the basic functionality working.
