I started a server recently, and don't know if it is intended, but the spell "Blazing fast" bufs all of the players on the server, and stacks when used by multipe players. Also the flames from the spell appear under AAI vehicels, that catch fire that way.

All the spells buff all players on the force, to prevent imcompatibility with mods like RPG System.
For Speed, there actually is a way to fix that.
That the flames appear under vehicles is intended - that's why friendly fire gets disabled for the duration of the spell.

Fixed that all players get a movement speed bonus :)