Re: 250kts on departure
never heard this recently (in the past year at least) to be honest unless you have a huge transit accross the TMA (eg towards dvr from the north and its busy) it does not make a huge difference time wise (max 1 mniute i reckon) so all in all if its the flow and possible reduction in being kept low or holding on arrival then it can only be a good thing.
Just to iterate - NO