When I run MM7 in software graphics, there are black lines and flickering all the time. In hardware mode the flickering disappears but movement becomes very stuttering and turning goes way too fast. Any suggestions?

I can't help with the other issues, but turning is set as default to 16 directions--meaning, with every press of the arrow key, you are facing in a different one of 16 directions. With an open game, press escape and that should take you to the game menu. Go to "controls" and under turning radius there will be three options, 16, 32, and smooth. Select smooth. That should fix turning.