Lower Max Spacecraft Speed

[Rockinsince87]

That could work. 

Would give a reason to have more then just rocket drive and gravity drive engine modules, and would make wormhole travel more appealing like you said. Or would you just base it on QL level of the ship? the drive module?  

Warp drive I think is fine as it is. Warp 1 is slow enough for sure. For me I feel that jump drive should be added and come after warp drive. Each upgrade improving jump distance. Require some kind fuel in the cargo hold to jump for balance.