2) If you have a "press here to drain SF and SR ships into my chipper shredder" button, then you could probably find a way to effectively use this new mechanic to neutralize both of those.
I don't think this should be a huge concern --- I think SF would be a great source for this new mechanic. It would be more organic than "a bunch of ships pop out of nowhere" and feel more like the AI being smart. Clearly this wants to be more than a meter --- a) it should be "fuzzy logic"ed enough that it's unpredictable to the player, and b) the AI should certainly be to decide not to stage this attack if it can see it's pointless, or to call it off if its losing. But it seems to me that this is a way for the AI to behave a bit more like a smart human player. I mean it should certainly be possible to use this to lure special forces into traps, but if the AI is able to use its normal degree of pseudo-intelligence I think it should be complicated enough to pull off (especially since it means being ready to stage the trap with a big hole in your mobile fleet) that it oughtn't to be considered cheese.