Good evening Squawkident.
In the London TMA the actual IAS, ground speed and heading can be selected for display, with the selected flight level being always displayed. We can also get the rate of climb/descent displayed as well, but this is a bit of a faff!!
As regards to TA/RA's, we have 2 stages of Short Term Conflict Alert which is derived by the radar processer. The first stage is where the aircraft which the computer judges that there may be a problem, the aircraft concerened flash white. We're told that it is roughly the time that you'd be getting a TA in the cockpit. The second stage is where the computer judges that there is a serious problem i.e separation has been lost and the aircraft concerned flash red. Again we're told that you'd be getting an RA.
From your post I assume that you fly into and out of Stansted or Luton. I guess most of your TA's are either in the BPK area when inbound, or when you climb to Flight Level's beneath the Heathrow stacks when outbound. When you're inbound, we tend to climb the Heathrow departures to FL110 against the SS/GW inbound we have dropped to FL120. If the outbound has a high R.O.C. then we get the white flash as the a/c passes about FL90 which I guess is when you get a TA. Likewise, when you get climbed from altitudes to flight levels ie FL70 if the pressure is 1013mb or above, if the R.O.C. is judged by the computer that it may cause a problem at BNN or LAM we again get the white flash and you the TA.
Hope this helps and as always you are more than welcome to come and visit us in sunny Southampton!