Yeah, always keep invite emails, take profile screens, note down passkey if you're extra diligent, store a .torrent file or the like. When something happens it's usually too late to grab the necessary proof so being prepared (if you care about the account or using it for something later) ahead of time is important. As for the screen, update it when something happens (e.g. you rank up or cross some threshold or the like). It's not crucial but the little bits add to the big picture and helps giving weight to your case in case details are ever needed.