Serious question, is there going to be an in-game map editor? If not what is it and can everyone use it?
Eventually an ingame editor will most likely be added, but not particularly soon. Currently it comes with a modified version of darkradiant with a tool for compiling+etc on the side. See the fourth slide on http://projectrik.com/ (click the arrows at the right side of the video).
And yes, everyone can use it :)
Also, will there be weapons for propulsion like in Defrag? OB's etc.?

Plasma + rocket type of things first time around, some more planned (damn, I need to make a video or sth with this, have answered this like 50 times now :D )

 
Overbounces, no. Wallstrafe, no. (Snapping, no.)

Obs are fun, but are trolly. As far as wall strafing good riddance. A video would be nice.
Yeah I agree, obs are good fun, but they don't really belong in any racing situation imo.
For now I youtubed the homepage loop video, you get a quick glimpse of rockets+plasma there 
Youtube video
you should consider making a QTDDOT for these kind of questions dini!
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Now I know!