Cyker: 2) The missions actually work as intended - In the Special Edition version, they shoe-horned the game onto the XvT engine; This has good and bad points. On the plus side, you get decent DirectInput controls and 3D Acceleration. The minus side the carefully balanced timing of a lot of the missions is totally screwed up because the XvT engine has totally different physics for acceleration/deceleration and laser/projectile speed.
Except they don't.
Dosbox has real problems with Big Ships and Platforms opening fire; set the core to auto and cycles to max (default setting) and the platforms won't open fire in a timely fashion, test it on Combat Chamber tie bomber mission 2, the platform won't open fire on any approaching ships unless you fire first, or sit next to it for a period of time (varies)
Go for normal core or a set number of cycles and you get crappy performance, increase the number of cycles to increase performance and the more cycles you assign you head back into the platform holds its fire scenario.