I know you can password-lock rooms that you entered first, but that's the only thing you can do.
I checked Gameplay-->Rooms in the Suggestions List, but it just says that /pw already exists.

So the concept is this:
You go to a room that doesn't exist, and you use a command, like /private, /claim, or whatever.
Once you do that, it's your room. You can password-protect it like normal, or you can make it so that only your friends can join, or only people you invite, which is an alternate way of locking rooms (instead of using a password).

If you're the owner of the room, you can also kick people.
Instead of having like ten people or whatever it is having to voteban (/ban) someone, you can voteban people instantly if you're the owner of a room.
You can choose how long they are banned.
You can ban them for as long as you're the owner of the room if you so wish.
Here's an example ban/kick command:
/kick <player> <time>
(I couldn't go with /ban since it already exists. If you use /ban, you can voteban like normal, even if you're the leader of a room.)
Here's an example usage of the command:
/kick Phonemouse 1h
You can use m (minutes), h (hours), d (days), and w (weeks).
You can also not use any numbers and just use p, which permanently bans someone.
Keep in mind that once you leave the room, every banned player gets unbanned and when you rejoin the room, if there is another person who have claimed the room since you left, you can't claim it again, but if no one has claimed it, even if there are mice in it, you can claim it.
Maybe to not make it too overpowered, make it so that rooms with over 6 mice can't be claimed, for example.

You can also make people moderator so they can kick/ban other players as well.
Here's an example command:
/moderator <player> <time>
(I can't go with /mod because it's already in use. It shows a list of online game moderators in each community. Maybe that command could be changed to /mods, so this room-moderator command could be /mod instead.)
You can make players moderators of your room with this command.
If you want, you can make them a moderator in a certain period of time instead of forever if you use the same parameters as the /kick command as written above.
If you do not include any time parameters, they are moderator for as long as you are the owner of the room, or until you demod them.
Here's an example command:
/demod <player>
This simple command can be used to make a moderator of your room a regular player again.
It only works if you are the owner of the room. Moderators cannot make other moderators regular players with this command.
An alias to this command could be /demoderator, which just does the same thing (which is why it's called an alias).

Owners of rooms can also play music with a command similar to the /musique or /music command in tribe houses.
Here's an example command:
/song <YouTube URL>
It's pretty much the same deal as the /musique or /music command in tribe houses, except only room owners can use it.
The limit on how long the songs can be is extended since only room owners can use it.
The limit could be, for example, 10 minutes (instead of the default 5 minutes in Music rooms, and probably with the /musique or /music command in tribe houses, I don't know).
If there's already a song playing, using this command will add a song in the queue.
The limit on how many songs can be in the queue can be, for example, 10 by default, and the owner can change this with this example command:
/songlimit <number of songs that can be in the queue at once>
The maximum it can ever be can be, for example, 30, and the minimum could be 1, of course.
Anyone can check the song queue by using this example command:
/queue
This command brings up a GUI window, or a list in chat, of all the songs in the queue.

The owner can give people permission to play songs by using this example command:
/songperm <player> <time>
Same as the /moderator command, you can choose to only give them permission for a certain amount of time.
Anyone can mute the songs using the /music or /musique commands.
The owner and moderators can take this permission away from anyone by using this example command:
/deperm <player>
The reason why they can't just use the /songperm <player> command again on the same player is because the owner or certain moderators may not know that a certain person has song permission, so they would just be removing their permission when they actually tried to give them permission.


Owners and moderators of rooms can also mute people who spam in chat, instead of just kicking/banning them.
Here's an example command:
/mute <player> <time>
The /mute command is not in use, at least not anymore, though the [url=transformice.wikia.com/wiki/Chat_commands]wiki[/url] says otherwise.
It's not like it's any reliable, anyway. It's really not.
Similar to the /kick command, you can mute players permanently (for as long as you are owner or moderator of the room), or temporarily.

If a moderator has banned or muted someone, once they leave, or once the owner uses the /demod command on them, all players that moderator have banned or muted are thereby unbanned and unmuted.
If the owner leaves the room or unclaims their ownership, all moderators and people with song permission are now regular players, and all banned and muted players are now unbanned and unmuted.
All songs stop playing too and the queue is cleared.

If someone with a song in queue, or a song playing, leaves, the song gets removed from the queue, or if it's already playing, it stops playing.
This is how it works in Music rooms as well.
If someone with song permission, or a moderator, loses their song permission or moderator status, their song gets removed from the queue, or if it's already playing, it stops playing.

The owner and moderators can skip any songs using this example command:
/forceskip
I did not choose /skip because such a command already exists.
Anyone, even the owner and moderators, can vote to skip a song using the existing /skip command.
Even the person who submitted the song that is playing can vote to skip it or force-skip it if they are the owner or a moderator.

The limit on how many moderators that can be in one room can be, for example, 5.
It would be quite a mess if everyone was moderator.

There can only be one owner.

The owner can also unclaim ownership of the room using the example command /unclaim or /unprivate.
When the owner does that, all moderators and people with song permission becomes regular players, and all songs stop playing.
It becomes a regular room.
Nobody, not even the owner who unclaimed ownership of the room, can claim ownership of the room again until 30 minutes has passed since the last owner unclaimed the room.

If the owner leaves the room, nothing happens until 10 minutes has passed.
Moderators are still moderators, songs are still playing, people with song permission keep their permission, et cetera.
When 10 minutes goes by, everything gets reset, and there are no moderators, people with song permission, all songs get wiped, and the owner loses ownership.
This is to prevent the owner from losing their ownership if they crash or accidentally close the game, which happens a lot, mind you.

Once the 10 minutes has passed, if the owner didn't come back during those 10 minutes, nobody can reclaim ownership until 10 more minutes has passed, similar to when the owner unclaims a room, except now you just have to wait 10 minutes (20 in total, counting the minutes you have to wait for the owner to come back).

People can claim ownership of normal rooms, Vanilla rooms, Music rooms, Racing rooms, et cetera.
Pretty much any room except for Module rooms.
Maybe there could be some exceptions, I don't know, but normal and Vanilla rooms can be claimed either way.

The owner can also pass ownership to someone else by using this example command:
/moveclaim <player> <r>
All moderators are still moderators, but the new owner can just demod them with the /demod command.
Same goes for players with song permission with the /deperm command.
Songs stay in the queue and everything remains the same.
It takes 3 minutes before the ownership is actually moved after the command has been used in case the owner uses the command by mistake.
If the owner does use the command by mistake, or makes the wrong player owner, they can just use the /moveclaim command again.
If they do not include a player, the owner remains the owner and the ownership does not get moved.
If they do include another player, the ownership gets moved to that person instead of the person they previously used the command on in 3 minutes.

You're probably wondering what the "r" means. The "r" stands for "reset."
If the owner includes an "r" after the username (space inbetween), the ownership gets moved in 3 minutes like nomal, but the song queue gets wiped, all players with song permission loses their permission, and all moderators lose their moderator status.