[PvK]

Increasing the default to-hit mod sounds like a good idea to me, although keep in mind that as technology increases, ships increase their PD to-hit ability from +70 (PDC I with no combat sensors or training) to +175 (PDC with CS3 and full ship & fleet training). PDC range varies from 3 to 5, which does tend to give an additional -20 for high-tech ships using range-5 PDC.

Since there is only one level of seeker defense modifier available, and ship fire accuracy varies by 105% throughout the game (and by +/- 60 or so per race, potentially), there isn't any way to really keep PDC useful-yet-possible-to-miss-with throughout the game.

PvK