I\'ve always felt that hyperspace (or any means of \'jumping\' spacial transit) needs to be really, really dangerous.
While I doubt we need to go as far as WH40k did and have the Warp be... Bad. Just... No. If that happens, I\'ll be happy in my sublight speed ship, thank you, I\'m not a fan of demonic posession and whatnot when it applies to myself...
Sorry, got a bit sidetracked there. Anyhow, yeah, Bad Stuff needs to happen if someone is careless with a warp drive, which would then encourage sublight flight, making battles occur in realspace, while Warp is there mainly if you\'ve got a long distance and aren\'t currently doing something else except in extreme situations.
How about... A damaged block whilst in warp will gain a DoT effect on it and it will affect other blocks nearby it, gradually increasing in effect and spreading. You can stay in Warp as long as you like, but only so long as your ship is undamaged on the Warp and essential things, which should be very hard to maintain.
Warp could work like an instanced tunnel of glowy lights which, if you hit the edges of the tunnel, you enter realspace, and if you didn\'t turn off your Warp Drive before doing so, you recieve MASSIVE DAMAGE.
This way, fights still happen, and people still spend some time in realspace because Warp, although useful, is incredibly dangerous, and thus cannot be relied upon, but still allows for tricky players to use it to their advantage. It also encourages the building of ships with heavy hulls to slow down the DoT effect of Warp damage.
Time spent in warp should be analogous to 1/3 of the time spent at maximum possible speed of that ship in realspace to reach that destination. So it\'s not instantaneous on well developed, massive servers, to reach likely targets.
Also, I feel that if there\'s objects in your sector you can hit, Warp driving whilst facing them should be VERY VERY BAD. Because suddenly going at high speed whilst gaining access to your portable glowwy tunnel, partly in-universe and outside it, into a city block-sized asteroid is likely to be dangerous.