Firstly, EW/MW/LW perks are applied to their respective arenas only. While that wish as already been tossed into the fountain, I would really like to see:
Heavy perks for FSO, Snapshot, TDI, etc to be applied to the arena of your choice (defaulting to LW)
By heavy perks, I mean something along the lines of 5 per kill, 5 per object destroyed (or better, per X damage to object so light bomber pilots don't get penalized) for FSO, quite a bit less for the unlimited life events, but still more lucrative than a comparable stint in the LWMA.
This removes the ability for people to sit and farm perks with a partner, as these events are monitored and structured to create an environment that would not be conducive to said behavior.
More importantly, it gives the CMs that pour a lot of time into setting up scenarios, FSOs, etc a neat little extra incentive for players to join in. Yeah, a lot of people don't care about perks... but enough people do that it might drum up some bigger turn outs for these events.