The Sherline High-torque motors

I have a Sherline 5400 CNC mill. I have always been frustrated by how slow the feed rate has to be when cutting aluminum. Oddly enough, cast iron and steel does not seem to be much harder to cut.

Do I understand correctly that if I install Sherline high-torque stepper motors that at the same speed and mill I can expect to cut at a higher feed rate?

Feed rate is set in the G-code. Changing motors will not make a difference.
If you use CAM software, you can set feed there also. (at the beginning of a g-code program look for something like F200, which in this case is a feed of 200 inches per minute.