Gathered a double Q&A for you:
Answered by product director,*Konstantiv Soldatov:

-New sounds and physics will be improved in the 9.15 patch. (RG: 9.15 and so on…)
-Like it was said before, SPGs will undergo rebalance. The devs want to pull arty into being a more supportive role instead of damage dealer. More details coming this summer (May-June).
-The match rotation issue that brings same map consecutive times in a row is in ASAP state/fixed as fast as possible. It was also stated that the problem is serious and it may take some time until we see such changes. * (RG: Haven’t they been saying this for years?)
-Devs are aware of the bug where the aiming reticle keeps on jumping and will be fixing it.
-The buff of certain premium vehicles (the list was published earlier) was requested a lot. It is not tied to the upcoming global rebalance.

Answered by product manager, Maksim Shuvalov:

-We are aware that the Polish tech tree is very important for the Polish community but there are already so far a lot of false rumours.
-Dev team is not 100% sure how the tech tree will look like because they are still gathering data.*Depending how much data they will find, the Polish tanks may have their own separate nation or just be thrown into a European tree.
-This is not a issue that affects only the Polish tech tree but a general one due to post-war construction.
-The historical department is working on various European nations*(gathering data): Polish, Hungarian, Italian, Swedish, etc.
-Historians looked for information in the*Warsaw University of Technology archives but many data has been lost/removed long ago because it was unused and outdated (engineering, etc). But fortunately there are preserved copies.
-We found (give or take) 12 projects. Sample of the documents:

-Polish Tech tree*is planned to be introduced in 2017.
-Why so late? We want each new tree to consist of unique vehicles unlike the Chinese tree which consists mainly of Soviet clones.
-Chinese tech tree was implemented to that WG could enter the Chinese market.
-Its possible that premium Polish tanks will be available earlier.
-I’ve heard of a HT invented by*Stanislaw Lem- Its a good idea to bring it to the game but only as a special game mode for an event.

-The previous game modes were a success (Chaffee Racing, Football/Soccer mode, etc) and we will be doing such things more often.
-TKS is still in testing phase, its not even decided yet if it will be a tier II or III.
See also:

-Devs havent decided if TKS will be a Regular or Premium tank.
-“Rudy? I was a big fan of “4 armoured” and I love this tank.”
-Whether Rudy will be in Polish or Soviet line is possible, its purely a technical matter. Its even possible that players get to decided that.
-10 Premium tanks will get buffed in 9.15.
See also:

-Rampage mode was not as successful as we would like but there are several solutions in view, all of which we are satisfied about and will introduce in the future.
-We cant personalize tanks for the time being because there are more important matter to concern about/direct resources to. We added too many things in a short time which messes up the game.
-We wont remove artillery nor make +/- 1 changes because it would not solve anything.
-Its complicated that various tanks of same class have different roles in the game, we are aiming to simplify that.
-I agree that tanks like MAUS that should be leading an assault are victims of gold round spam.
-Artillery is cumbersome because of its long reload times and high amounts of damage it deals to opponents, we will be changing this class to fix that. (RG:See*Konstantiv Soldatov’s answer on the matter*above).
-We are working at the moment in a complete rebalance of tanks, crew skills and many other interface details.
-Several new tanks and maps will be introduced this year (RG: Don’t forget that Storm said that the team is planning to have less but better maps, most likely they are replacements of the crappy ones we have so don’t expect more maps).
-We will be further*diversifying*the sounds in-game.
-The new sound engine uses a different core than the whole game but we are working on it so the GPU doesn’t get so abused.
-Team is working on “HD” maps
-We are not giving up on BigWorld because we are continuously improving it, Its server part is what we have worked the hardest to make it work and we will not abandon it because we are satisfied with the results.
-WoT Consoles look good and we are aiming to do the same with the PC version. We will be testing weather elements *viability.
-A third server for EU? I know nothing.
-We are debating the possibility of adding a positive reward/report system like in WoWS.