The original constitution forbids all of the following except

If you are talking about the original constitution as the U.S. Constitution, well, it doesn't forbid the legislature to be bicameral. (You see, the Article of Confederation makes the legislature unicameral.) Also, there was this citation saying "The original Constitution forbids all of the followings EXCEPT suspension of free speech limits on the prosecution of treason ex-post facto laws suspension of habeas corpus." 

Hope this helps