Typically yes, you could counter the ability though. I think the weirdest part is "as your land drop". That means it would activate for free if you ramped it out?
Yeah, that would be my assumption. "Playing" the land requires paying the cost, but pulling it out from a Crop Rotation or Growth Spiral wouldn't cost mana.
And yeah, of course the triggered ability could be stifled, but let's be honest, who's running stifles?