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.
The username is a unique identifier of your account 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.