First off, tack 2 or 3 zeroes onto the end of all existing VXP and tokens, as well as the XP levels needed to level up so you have room for different levels of points awarded.
Starting with the tiniest ships, such as lvl 1 cargo, make each ship killed worth 1pt. The bigger the ship killed, the more points.
Next, ACTUALLY MAKE KILLING LAND BASED TARGETS WORTH SOMETHING. Same with ships, scale it depending on threat level.
To address the issue of people suiciding zombie fleets to collect death VXP, that will need reworking as well. Make every 1000 or so POTENTIAL damage worth 1 pt. This should apply whether or not the damage was taken, evaded, reduced by Survival, or Countermeasured. Additionally, if the ship counters damage intended for another ship, the ship firing the countermeasure should get the XP for that damage. These changes would alleviate the suicide payoff and properly reward support ships such as tanks and countermeasure support ships for contributing to the battle.
I believe this would reward players more for participating in higher stakes battles to gain VXP.