I have an idea that will make life more pleasant for a lot of players, and also Gaijin will not do any damage.
It is about the EP once you have a complete techtree ready. Currently it is so that the EP disappear, and that makes you really mad, it is no fun to play the vehicles from the techtree.
Now comes the idea:
The EP are stored in a monthly pool, and are converted into SL. What does 1EP = 1SL
For example, at the end of the month I have made 500K EP in a finished techtree, now get at the end of the month 500K SL. So playing has a meaning.
Now you can also expand it. Premium accounts have a 1 to 2 conversion.