Just a reminder, this is kind of the ‘screw around’ room so any volunteer here probably isn’t looking for serious questions.
But, in brief, no.
We can delete all of your votes which will make your Favorites disappear, but they won’t just be hidden - they’ll be deleted.
And for your comments and posts there’s no way for us to hide them. Sometimes, if someone has only a handful of comments or posts we can do it by hand - but any replies to those posts remain as-is. And you’ve got thousands.
But, and I know this is a serious question in a non-serious thread, why do you care? No one knows who you are - you’re just some rando on the interneto with a name that doesn’t tie to you in any way.
Why do you care that someone can see that some profile named “Abandoned Account” on a my little pony site likes this drawing or made that comment?
If you logged off and never returned to the site, would anyone ever know or even care that it was you?