Troops are issued with PLCE (Personal Load Carrying Equipment), some troops buy their own, or they can get their hands on the PLCE assault vests.
As for the body armour im not to sure about this but it is apparently quite good for stopping rounds, but a gap is caused apparently (correct me if im wrong) around the arm area leaving it exposed while shooting. As for the webbing and the body armour the new Osprey and Kestrel (Kestrel being the one that is used by 'top covers' on land rovers because it gives better protection from I.E.D's, because the user can add extra plating around the neck, groin and arm areas) have loops (similar to the American MOLLE loops) attached to them in order for Ammo and Utility pouches to be fitted on to the users personal prefrence.
You're thinking of design elements in some vests that are designed to minimise shrapnel penetration should the main armour fail. The jacket compresses around the point of impact providing support and pressure to the injury. Not sure if our current batch does it, but I know there are some out there.
Right, first of webbing we get issued is good for what it is so don't worry about that, and quite often you will be able to get hold of one of the issue assault vests though i do have some issues with mine a bit of tinkering and stitching will hopefully sort that.
As for the body armour what you are referring to above is CBA, the stuff you get issued for use on the range etc will do nothing to stop around unless your lucky enough to get one of the new sets which holds the plates and also you get some plates, if you are however in Iraq or Afghan you will get all the body armour you need because remember your the one who is gonna be yomping it about all day.