As a comment:
The Rambo Rome Invasion has little or no risk, but offers a high reward. There is also no real defense. So, it should be banned. With all the other moves or actions there are disadvantages to potential counter-balance any advantages. I think it is important for players to be able to be innovative and creative in their strategies so as to make the game more interesting and challenging. There are clear risks or disadvantages (eg., increased USA or USSR readiness) associated with the Spanish Gambit, LC Gambit (especially on turn 1) and the Italian Gambit. That is why they are called 'Gambits'. If a player wants to take such a risk as part of their strategy then I think they should be allowed to do so.
I think Hubert has done an excellent job of creating a balanced game that allows for creative strategies. A decision by the Allies to declare war on the Low Countries, Spain or Italy has to be weighed against the delayed entry of the USA and/or USSR, and the risk that the attack will not go as hoped or planned.
Let's encourage -- rather than discourage --creativity and imagination.