Village protection and the protection of the game is too important, it wouldn't do imprisoning only nin of your own village. Besides, then I could go to a village, write a huge post insulting them, leave with the missing nin bug (which is allowed since I am a sennin) and they couldn't do anything to me.

And making the XXX place public is just asking for abuse.

well actually imo it wud be a good idea to only imprison Your own villagers...
BUT thats only if the ambassadors thing became a weekly/fortnightly/monthly thing.
i.e the kages all interact with each other and exchange information, say if an ANBU is being a nob and does what Pyro said then the Kage of that village will imprison him.

also its just a guiideline =)
ofc if this "guideline" was implemented it doesnt mean Kages CANT imprison villagers from other villages. obv if there is a really serious criome then Kages should be able to imprison anybody.

but for petty matters then it shud be left to their own kage.

i hope this makes sense =)

This can be done only if Martin set a cap on it which will never happen.
If you go and tell to a new player " you can use this only until you are level 20" do you really think he will stop at level 20 ? There is another problem. He can stop at lvl 19 and start using the ramen to make money. So you will see a low level getting awfully rich which will destroy the balance of the game.

Until Martin will make this place a feature of the game and set a limit of how much it can be used this place should be forbidden.