Slow down and speed up as in the planes fly very fast and are very sensitive to handle? and then like when your facing the sun it slows down and the controls don't feel overly sensitive?
This happens when the FPS gets too high (I know, there are those that boast they get 150+ FPS with this game, but everytime I start to get in the 90's, especialy 120+ I tear the wings of with a twitch on the JS).
Using Gide helps as it makes the game use more resources, which helps slow it down, and therefore makes the controls less sensitive. Then adding modded Terrain like Promise Land 2 helps knock a few more FPS off and makes the game that much more prettier.
For Glide Wrappers, you can do a Google search for "Glide Wrappers" or use the ones I have uploaded on my Skydrive: https://skydrive.live.com/Wailwulf/GlideWrappers
The one I am currently using and like is the one called CJglide2x_02 which is a single dll file that one puts in the game folder. But there are a number of other Glide Wrappers hosted there as different computers seem to like different wrappers.
My current machine, Win7, before I started using the CJwrapper, only liked DGVoodoo 1.4, where most seemed to prefer DGVoodoo 1.5. On my old XP machine, it was the OpenGlide one that worked best for me.
For the Promise Land Terrain, the best place to go is here: http://www.rb3d.net/Swordfish/links.htm
I prefer PL2 over PL1, but that is because I am one of the ones whose Win7 computer crashes the game when exiting the mission with PL1 graphics. Seems to have something to do with the custom color palettes, though there are those that have no problems with PL1.
Sorry, do not know how to edit the criteria for promotions or awards. But if you wish to do so manually (Hex Edit) These archived pages of Sygrod's site are extremely helpful: http://web.archive.org/web/20060813005805/http://home.golden.net/~ksharman/rb/Main.html