I have so many achievements that I Can not get because they are event achievements and I was not active during them. I also have a few event items that I may have gotten the one or two times I did get on within a few years, like moonbricks that I can't do anything with and why is the marketplace full of items I can buy that are not even buyable because they were event items? The most annoying part though is scrolling through the 50 impossible achievements though.
Email support to get rid of any items you don't want to keep. As for achievements, maybe be a little less self centered and stop obsessively scrolling through them.
I agree, support. Time based achievements in the past should be eliminated from a player's profile if they aren't earned. My favorite is the bronze dragon egg collector from 2014 (I remember earning a silver ranking). Also support on cleaning up the marketplace / misc profile items.