Do not try to force people to play the game the way YOU want them to play. Everyone plays this game for a different reason. The best way to encourage PvP is to better insensitive it. Make people want to come out of the safe zones.
The issue is, most veterans will not be around their own Safe zone, they will be out in the world doing things. When a enemy fleet rolls upto another Nations safe zone they will rarely face another Nations veteran players, they will face the new players who are just getting started or the PvErs. Which normally ends in the attacking Veterans steam rolling the opposing side. If you took away the safe zone you would just find new players seal clubbed by the so called 'Vets' and 'Elite' players until they quit and your population will tank heavily.