Wasp

You can terminate an international manager's contract with the in-game editor, if that's what you mean. You can also move him to your club but since he's a manager he'll just replace you ...

There is also an option to hide it in the preferences menu. You can reactivate it when you need it.

I used exactly that midfield setup in a 4-3-3, it worked pretty well. I did play my best midfielders at those positions though, two great advanced playmakers basically.

I'm trying your ideas with a DLP in the DM slot. I use either a converted winger or converted full back in the midfield winger slots, depending on the strength of the opponent's wide players. I'm not too sure on the AM - CF pairing yet, although their technical skills have produced some wonderful through balls already.