A way to remove Squatters

A way to remove players who "sit" in the game while it is not game time is would be nice. It is kinda annoying having someone sitting in there while work on your adventures.

Just create a "welcome page" with the details for the next game session, and put the player bookmark there. Then you're free to do anything unobserved - except perhaps test macros if that'd give anything away.

Yup, I have an OOC room I let my players mess around in as they please. It contains my players' tokens, some text on the map layer (saying basically "This is the OOC room"), and a bunch of stuff my players drew. They regularly show up for the game before the scheduled start time, and before me, so it's useful.

I have one of those as well, with all the availible tokens for them to pick from. But I still want a way to kick people out of the game without removing them from being a player

I don't see why you can't just ask them to come back at game-time. Unless there's some sort of disrespect going on between you and the player(s) in question, they should be willing to respect this request. Otherwise, as stated, just disable video and voice and putting them on their own page (which could even be direct with just a text saying "GAME TIME IS XX:XX on mm/dd/yy, come back then." should handle what you want. as for testing macros, whisper yourself with them. Otherwise, present or not, a player could scroll back up and see them anyway.

As a mentor, I have created a separate campaign board and test everything in it then use the transmogifier to pull the work over to the main game board.

Some people just forget to log out of the game when it is done lol.