It sounds as if you have large hands that make operating a Leica M difficult due to their relatively small size. Is that the case?
Another thought is that your rangefinder mechanism may be out of alignment. If that is the case, it would explain at least part - if not all - of your lackluster image quality. Sherry Krauter in NY
[ www.sherrykrauter.com ] is who I would recommend to have evaluate (and repair if necessary) your camera, if you are committed to keeping the camera.
If the issue is that the camera is just too small for your hands, a halfcase with built in grip from Luigi [ www.leicatime.com ] might remedy the problem although I tend to agree with Roger about halfcases. They slow the film reloading process considerably.
Still, a half case would be preferable to selling off the Leica gear, at least for me.
Just my opinion - let us know how things work out for you.