IT's unreal what you describe, sometimes you wish you could reach through your headset and grab the pilot on the other end and shake him!!!
I had a flight a few weeks ago that did something to me:
my call " xxx air descend to FL 250"
pilot "XXX air cleared to FL 250, do we have to start down now"
my call "sir, descend means descend, yes start down now there is traffic"
pilot "well sir, if you want us down you have to say descend now"
my call "read the rules, i did not say cleared to or descend at your discretion i said DESCEND"
How much clearer do we have to make it. I say climb, then climb, i say descend, then descend. You want safety then play the game boys, we don't do this to piss you off.