I know you're gonna hate and kill me for this idea, and I know it's not going to happen, but...
The solution to the immense ammount of perk points everyone has is to perk all the heavies. And to keep the light/mediums free. Anything with four engines (heavies), goes down the perk system with reasonably low perk costs according to it's loadout (say 1 or 2 perks for the B-17, 2-3 for the B-24, 3-4 for the lanc)... twins (B-25s, B-26s, Ki-67s, Boston IIIs, A-20, Ju88...) and singles (Il-2, Stuka, SBD, Kate, Avenger, Val...) stay free.
And the 234 of course, stays perked.
You get to see more early war and lighter bombing aircraft you rarely get to see today (any buff you will find is 90% a B-17, Lanc or B-24), and there will still be a lot of four engined bombers flying here and there because of their reasonably low cost and because most people has a lot of buff points anyway.
I love the idea of seaplanes, too. But don't really know how they could be implemented in the gameplay as it is...maybe making enemy fleets appear on the map of everyone on his country if it's shadowed by a seaplane can be an idea, but of course then there is the question on how hard would that be to implement (without forgetting that big seaplanes are hard to model and probably are very low on the priority list)