You are correct, while driving under "emergency conditions" the driver is exempt from SOME aspects of the RTA;
they are allowed to exceed the speed limit WHERE SAFE TO DO SO.
they may treat a stop light as a give-way light AT THEIR OWN RISK,
they are NOT permitted to cross solid white lines to overtake slower traffic,
they are NOT permitted to go up a one-way street the wrong way,
they are allowed to park on yellow lines, or loading /unloading lines, in pursuance of the emergency,
They have NO right of way, no right to force other drivers to take avoiding action and may only drive "in safe manner", failure to do so may and does result in prosecution and losing one's licence is not an uncommon experience......
Once again, that is all from memory, it is a number of years since I was last in that position in a large white van with odd lights and nee-naahs on it.....
I have to say, if driving in London during rush hour, forget the blues and two's they are a waste of time.....
In Devon, if on blue lights and with the audible warning devices activated (choice of three different ones), the common response of drivers was one of three;
1. speed up and race the emergency vehicle (not a good idea, illegal probably and I simply dropped right back....),
2. slow right down to a pace where the average snail would overtake, in the hopes that the emergency vehicle would go past (not always possible or safe, so once again this often resulted in me slowing down to allow the driver to sort themselves out and find somewhere safe to pull in to the side),
3. make an absolute diving turn to the left, irrespective of who or what was already there (one driver found the space he wanted to be already occupied by a concrete farm gate post.....), once again, I slowed down and gave them room, hoping that they did not hit anyone or anything meanwhile........
I preferred them to go forward normally and find somewhere safe to pull in, preferably long before I got near them, but sadly many drivers do not have rear view mirrors fitted (obviously an optional extra - not), and do not hear the rather loud noise generator behind them - possible because some people ARE deaf, many others acquire deafness from their music system up so loud it drowns out the emergency warnings (equivalent to a directional 250w amplifier I was told but I am not positive about that) they can produce 110dba at a distance of 30m in front of the directional speaker (mounted behind the radiator).
Do I miss it? Yes and no, I miss helping people, but not the noise which is intense in the cab (up to 80dba) which can cause hearing damage....... even with the windows closed......
Dave