Some quick questions

I found out about this tracker recently:D

If you are a new user, does the tracker look through your past killfeed and update achievements like hardmode? Or will others have a huge lead.

Does the client software have to be running to get stats like achievements? Is it sufficient to just register and have stats tracked automatically, for instance if you're having performance issues like hitching and run minimal background processes.

Thanks

It isn't retroactive, so you will be effectively starting at zero, with the people at the top having a considerable lead on you achievement score wise. The tracker has to be running to add achievements to your character/account.