Everything here is in Viewing Preferences and changes what you see, not what anyone else sees.
Piczel hosts adult work alongside everything else. Control what you see with the content visibility setting.
Auto-play streams controls whether a stream starts playing when you open it. It is on by default.
Performance mode in large multistreams controls whether large multis start with the Streamshots player selected or not.
Piczel warns you before opening an off-site link. If you trust a destination you can add it from that warning, and links there open without the warning afterwards.
Which emails you get, and what a new follow subscribes you to, are in Emails and notifications. Whether a person's favorites show in your feed is a per-follow switch in your follows list; see Follows and followers. Player layout and quality are in Watching streams.