You can change the color of rows with ‘Actions > Modify category, description, location, notes, color etc.’
You can’t pin or hide a row. Not sure why you’d want to disable it unless the goal in that case is to color it. However, now you know how to color it without disabling it, so hopefully that gives you what you need.
As for it getting in between real hosts when sorting, you should be able to easily at least force it to be at the top or bottom just by naming it accordingly. So like you could name it zzzzz or aaaaa or ….. or whatever makes sense. Then it won’t get put between other rows when sorting. It will only go to top or bottom.
-Doug