Hi
At the moment we have a warp cap of 6000k.
With the items now in the game, a number of professions with the right equipment can reach this cap. The rest can get over 5000k.
In regards to signature, again with the right equipment, the Jenquai can get to 0.0k sig, the terrans close and the Progens can get a significant drop.
It is all a matter of balance and trade offs. Players have a choice of how they setup their ship. To create engines that give you 6000k warp and 0.0 signature seems to me counter productive. Part of the fun, at least for me, was to acquire the right equipment to accomplish my goals.
I used the highest lvl engine I could in live because with the increase in thrust, it allowed me to continue to move when hit with mob gravlink.
So, I guess what I'm really saying is, I can not see any reason to make changes to engine stats.
Riia