On the first question; is this a new problem? Was it working before?
if separate, are both core and remotes on the same release version? And have you tried rebooting?
If you are using a NUC, have you added the required codecs?
I’ve moved your post to the #support category as something isn’t working as it should. If the options I have mentioned don’t work, then it will help if you post details of your setup as explained here
On your second question, it’s a matter of convenience for the user; if you have a few favourites then put them all in one place rather than search for them each time.