As other have also suggested; remove proposed war feature
-if you want to diplo your war starts you can still do that... but you can't get a war without making a hit, multiple in fact

Buff Hostile gains/nerf the GBP ... even offer some gains(vs the target KD only) or other perk to the aggressor KD when they give Hostile relations out.

Cap Hostile meter at 75 instead of 150- lets see some auto-wars, or lets see people get punished for not retaliating.

As far as meter disparity; have gains throttling kick in at 50 points difference(instead of 100), and have the reduction increase linearly to -25% gains at 75 points disparity.