Wow this board is from last year. Sorry I didn't see this but here are the answers. There are multiple tiers to these achievements, that is why you are getting the events more than once. As for the skins, when you go to the skins tab, there is a button that says to remove it. You cannot have the base avatar and a skin at the same time because the skin is replacing the base. There are ways of covering it but that is with actual wardrobe items (I am working on a virus right now but I have it covered).

Being able to wear the koi skin even when it is greyed out is an issue that should be fixed with the new wardrobe.

Although we don't have a necro rule in Problems and Bugs, it is better to make your own board if the issue isn't the same. I don't think in this case that the issues are the same in this case. If you go to https://sapi.subeta.net/avatar/hexes/base/642638.png you can see what stage your virus is in. You are currently on Stage 2 which is about normal. You can see the stages at the bottom of http://www.subetalodge.org/page/name/2009_virus_strains.

I hope this helps!

Yeah with the achievements there was a point where you had to have imported your achievements but that was years ago and I think there is no way of doing it anymore. I can ask if you would like me to?

Sorry about the koi skin though. That is a really weird situation. The good news is that you'll be able to get it again this year for Morostide!