As far as the mouse, I never could make use of a regular mouse. My hand just won't work that way. It's the most unnatural position I could ever imagine being designed for this. So I looked around at different kinds of mouses (mice?) and settled on a touchpad mouse. Not the crappy ones that come with laptops.... But anyway, you might want to look at trying different kinds of mouses. There are a few, maybe even several different kinds.
Or you might want to consider using a graphics tablet. That allows you to draw in Inkscape using a device like a regular pen or pencil.
There is a key shortcut that I think can keep the handles from rotating, but when I looked earlier, I couldn't find it. Let me give it another try, and maybe I can find the right one.
But on another note, I'm having a hard time understanding how you want it to work. If you want the handles of one node not to move at all, when you move the node, you need to select the nodes on both sides of that node, and move all 3. This is really how vector graphics works. I guess I've never used another vector graphics program, but I have the impression they all work like this, where moving a node makes the handles move too.
Can you show us an example in an SVG file, and explain what you want to accomplish? I have a feeling there's probably another way to do what you want, but you're focused on the node, when there might be another approach.
But meanwhile, I'll try to find the shortcut I'm thinking of.
Edit
Ok, the shortcuts that might help you will be on this page:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Paths-Editing.html#Paths-MiscBut again, I have a feeling there's another way to do whatever you're trying to accomplish by keeping the handles from moving. So if you could show us an example, we can probably find a way to do it.
