while there have been talks about doing a run like that, it probably won't be its own category as it's far too long and is different for each platform (the number of mobile achievements for example, hoo boy...)
if it were to be a category, it'll likely go in to the category extension leaderboards.
Worst achievement is probably Lucky Spin, or the achievement where you unlocked every plants in the Zen Garden...
I don't think anyone can do such a run without a break, it's a 15+ (minimum) hour-long run that requires skill throughout all categories. Also, I am unsure of how to reset your achievements on Steam.
Though if anyone is interested in such a thing, don't let the idea of it not being on the leaderboard prevent you from running it as this is something that has been talked about for a long time and I think it would be amazing if someone can pull it off.
UPDATE: All Steam Achievements has been added as a Category Extension. Have fun! https://www.speedrun.com/pvzce#All_Steam_Achievements
