Add fake time and limit number of points

[routeconverter]

My GPS device only accepts gpx files that have maximum of 2000 points and also have the timestamp added. Is there a way to add faketime to all points?

Yes, try Complete->Time which adds timestamps between positions which have a timestamp.

Similar to what gpsbabel offers? Also automatically discard points so that 2000 remain?

Thats at Position/Delete Duplicate Positions...