I will  have to think on the use of antimatter further - when I'm not as tired as right now. I may develop a sort of "tech scale" and put a general stop at some point, right now I am thinking

Fossil fuel < fission < fusion < antimatter < subatomic < exotic particles < subspace < singularity/gravity < ???

I am just not sure whether for the cap to be right short of antimatter usage or subatomic particles - the latter is a no go that's for sure. 

Point is, civs in this RP are still very young. It took humans 250 000 years to go form fire to very basic space program, and here you are reaching for the stars in just 10 000, likely because of the 'libraries' found on each of the homeworlds (I may have to edit that timeframe yet). 

As far as the warp drive goes, I guess it depends on one thing: What happens when an object using it DOES crash into something? Because you don't have to be mounting it on just ships.

FTL sensors are good, just remember though that using any active sensors is basically yelling "I AM HERE SHOOT ME".

Now, i seriously need to sleep xD