So in your game, you'd want the PCs to be insulting and/or stabbing each other in order to gain combat advantage against their enemies.
... I don't think we're even writing the same language here. I cannot see how you can jump to this conclusion from the text I wrote.
Yes, if I were the DM I would require you to do something offensive if you visibly tried to metagame the system by pretending one of your allies is hostile one moment and then an ally the next.
Yeah... no. If you can't see how ridiculous that is, I can't help you. Better IMO to just rewrite Warcaster. The suggestion up-thread that it "lets you substitute a spell with an attack roll for an opportunity attack" would be reasonably straightforward.
The only ridiculous thing here is the contortion necessary to draw these conclusions. I give up. Go ahead and have the last word - I'm clearly unable to communicate with you

Incidentally, Haste would be an awesome spell to cast on enemies, if you could find an enemy willing to have you cast it on him (due to trickery or whatever). Auto-stunlock for one round, no save, as soon as you end it, which you will do at the worst possible time.
Now, this is true. Charm person or Suggestion would do it, for a cost of two spells for a one round stunlock, with a save. Not really worth it, I think, but it would be a lovely way of betraying another PC/NPC who thought they were your ally.
Actually, I think I need to use that at some point...