A few answers to some of your questions, in my humble opinion!:
Yes if you're high on the profile initially you should increase speed, and then use speedbrake to increase rate of descent (RoD) further. If you need to increase past that, or are told to slow down then you can think about changing the config (flaps and gear). Which mode you use is up to yourself, Open descent is generally the best for increasing speed, as it will dive to reach the higher airspeed (make sure you keep an eye on TCAS as you don't want to trigger a TA/RA!) V/S can be used however at upper levels it generally isn't, it is used more as you get towards the ground and want to 'fine tune' your RoD.
As for the A/THR adding power against speedbrake, you need to full understand exactly how each of the modes work. Open descent will always have THR IDLE and will pitch for the speed. In this case, using the speedbrakes will simply increase the rate of descent, the power will ALWAYS be at THR IDLE. V/S pitches for the RoD that you have requested and the A/THR will do its best to match the speed. I.e if you have a high RoD then the A/THR will reduce to idle however the speed may well increase if the RoD is high enough. In this case the speedbrakes can be used to try and hold the speed back. If you have a low RoD selected then yes the A/THR will increase thrust to match the select/managed speed. If you use speedbrakes now then NOTHING will happen apart from the A/THR will increase thrust to keep the speed. The RoD will not change since the aircraft will pitch to maintain it no matter what the speedbrakes are doing.
Also you are correct in saying that the A320 cannot use speedbrake in conf Full, however the A321 cannot use the speedbrake in Conf 3 OR Conf Full. The A318 I believe can use it in all flap settings, but am not sure.
Basically as other people have said, above FL100 it is a good idea to just increase the speed, unless of course you have a speed limit! You can also use speedbrakes to help. Speedbrakes work much better at high speed.
Once below FL100 and are starting to slow down in the terminal area (it really isn't a good idea to come barrelling into the terminal area doing 320kts!) you can then consider using flaps. Conf 2, speed 180kts and the speedbrakes will give you a very good rate of descent, and will usually allow you to meet any speed restrictions ATC have given you. If you are still too high then you can throw the gear out.
Both the gear and speedbrakes can be used if you are too fast. It is quite common in a tailwind that you will struggle to slow the aircraft down, in this case select a low RoD and use the speedbrakes to reduce the speed.
If you are below the profile then you can reduce the RoD as needed, the A/THR will keep the speed selected.
One great bit of advice is that you NEVER want to have a RoD that is equal to your current altitude. I.e if you are at 2000ft then DO NOT have a RoD of 2000fpm or more. You are 1 min away from hitting the ground which is never a good place to be!
Remember as well, if in doubt then ask for more track miles! There is no shame, and I know a lot of airports that have ask me to do impossible approaches! ATC often don't fully take into account the wind etc.
Hopefully all of that has been helpful!
Last edited by Blinkz; 4th August 2012 at 08:51.