There is nothing to stop you abandoning your castle and starting a new game in a new Kingdom if thats what you want to do.
Why do you need to reset your account?
Have you lost your novice jump because your castle is over level 5?
If you want to reset so you have a novice jump, it will be used to go to another Kingdom so you will be no worse off , if you just start another castle in another kingdom and use your novice jump to join your friends in theirs.
You could be lucky and find yourself in their kingdom.
Alternatively just keep your current castle and get it to level 21 as quickly as you can ,and get Drakkers to move it where you want it to be with your friends.
It can be surprisingly quick to get to get to Castle 21.
However you can just leave it there you may decide to do something with it later.
Just for now abandon it,set up a new game, you will need a different email address.
Get your new town in a new kingdom.
Unless you are really keen to move to the kingdom that your friends are in, think about staying in the new kingdom and gain all the benefits from being there, and then move to be with your friends.
DONT FORGET ,
ignore the game when it tells you to go to Palace 6 ,or you will be stuck again.
You can also think about playing your present game in between a new game and use it for practice , even if you never do anything else with it.
Yes you are probably right a reset button would be a good idea for the player who has made a mistake.
Though the people who run the game probably like the way it is now.
Wait.. I think you can get support to completely remove your account, which might mean you can use the same email