There is no race gametype, per se, but you can set up a version of VIP with checkpoints. In Forge, you edit the VIP game type and add the check points. It's not quite the same, though. You can't do laps, only a single series of checkpoints. Forge limits you to how many checkpoints you can place (and it's pretty small, like 8 for Sandtrap). Forge also has a lot of goofy limits on equipment and weapons that make creating something to your vision quite difficult.
The biggest problem, though, is that each map will be a custom game that you have to organize with your friends... there are no server lists or hosted game lists or public matchmaking lists for custom games.
The rockets don't track, but watch out for missile pods... the missiles DO track. Just don't put any in your custom game. Also, plasma pistols will stop vehicles for a few seconds... so they're good for hog jacking.
You can do campaign in co-op with friends, but you have to arrange to meet online and join together. The co-op has settings to where friends can join at will or by invitation only. You can organize a party for campaign or to play matchmaking together. Social doubles is fun... you and a friend can make a party and take on other pairs.
Pongo (gamertag HamarSkald)