I would personally like to see:

1. PC matchmaking

2. RNG retooling. There's no reason a tank at 100 meters should miss it's target when fully aimed in unless the barrel is damaged.

3. Ammunition options specific to the vehicle and nation, for example, sabot for late war British tanks, shell/Fuze combos for arty, etc.

4. Stop with the buffs and nerfs. Program the vehicle properties close to the historical specifications and leave it alone.

5. Add some new countries' tech trees.

Most of the problems can be fixed by not fixing what isn't broken.

That being said, thank you, Wargaming, for this game. It is my go to and I appreciate the work and effort you guys put in to this. Please feel free to message in regards to wish number 3. I can explain in depth.