Agree with all the above.
I'd also like to make the point that, in order to "catch up" with our staffing plan, there is almost continuous training going on these days. Whilst many of these trainees will make excellent controllers, the vast majority no longer come from aviation-enthusiast backgrounds, and have to be taught what used to be instinctive. I'm fairly sure that, in the example above, the instructor would have discussed the situation with the trainee later, over a cup of coffee, and, hopefully, that particular individual will not ask for the impossible too often in the future.
That said, as also mentioned above, sometimes we DO have to ask the impossible just to make the system work. Sorry if it gets uncomfortable, but thanks for giving us that bit extra when required.
As for a rate of climb or descent for expedite, use the pitch of the controllers voice as a guide, and then add 2000 fpm !!!