You can define as many users as you want. The users do not already have to be created in the backend. Just insert them here and create them later.
Default Text
If you add a new block, it is empty per default. If you want to provide some standard text, you can do this with the defaultText option. The default text will be shown when ever the content of the block is empty. So if you delete everything, the standard default text again.
<?php$scms->text("BLOCKNAME",["defaultText"=>"This is my<br>HTML default text"]);?>
Text only
Per default, the SingleCMS blocks get surrounded by a <div></div> if that does not suit your use case you can render the block as text only. In this mode only the content does not get surrounded with the <div>