One thing I have noticed is the dissatisfaction a lot of players experience with the 12 hour change rule. This doesn't really apply to me as I have so far picked squads that stay solely in one particular country through thick and thin, but I did have this thought:
1) get rid of of the 12 hour time change rule all together. Allow players to switch freely over to countries with significantly lower population levels. I know ENY and perk bonuses are already in place to regulate this but, let's face it, you can't fight green guys...that is generally frowned upon.
2) disable friendly dot locations over the entire country. Make it so friendly country mates are only displayed within a friendly enabled radar ring and above NOE level. Only squad mates and those active on vox/range channels would be displayed regardless of altitude and radar status. Friendly/Enemy dar bar would still function like normal. This would provide some level of security against "speiz" (for those who care) by not allowing all background country members to see the big picture. (E.G. If a friendly mission is NOE, then no player outside of squad/vox/range affiliation will know what is going on to potentially alert his/her friends on the other side of the fence).
Sure there are ways around it for those willing to engage in such methods, but that is my thought for reviving the arena when population levels are skewed.