Concerning the wheel brakes, there are tonnes of other threads that can help you find out how to use them properly.
If you're flying with engine at idle, that does not mean off. A small amount of thrust is still being produced. Turn the engine off, wait for total spool down and then see what the glide ratio is. According to the 1F-86E-1, the glide ratio in clean condition is 14:1 with speed maintained at 185 kn (giving 2700 fpm descent at 40000' and 1500 fpm at 10000').
I don't have time to test it now, but see if you can replicate those results. Based on how hard it is to slow down and land, I may agree with you, but we'll have to confirm with an actual dead engine.