Enabling it will allow other administrators to know that you are mainly federating sensitive content.<x id="LINE_BREAK" ctype="lb" equiv-text="<br/>"/><x id="LINE_BREAK" ctype="lb" equiv-text="<br/>"/> Moreover, the NSFW checkbox on video upload will be automatically checked by default.
The channel name is a unique identifier of your channel on this and all the other instances. It's as unique as an email address, which makes it easy for other people to interact with it.