Is there a way to only show the sets I have installed as it’s a real pain to scroll right to the bottom of the list on my phone to find Matt Mercers files etc.
In the top left corner is a button labeled “all soundsets”. Click this and choose “installed” - and you’re done! 
Yes, and check out the Campaign Manager in general (available on the homepage of syrinscape.com when you are logged in)… with this you can make all sorts of Playlists for this column.