Who F,
trying to answer your questions:
Yep, the CAA have generated a change to the Police Air Operations Manual (that we all have to comply with). Police pilots generally don't have to be IR, but we all did have to do IF training. As a result of the Strathclyde accident (and one or two others) the amount of IF training is to be increased. The CAA has pledged that we won't have to go IR "for at least 3 years". the cynics amongst us, used to politicians pronouncements, might regard that as a schedule by another name.
Some current UK police helicopters are not IFR certified. IFR certification for the UK is more onerous than for some places.
The other big problem to proper IFR is fuel reserves - it is a problem for any IFR helicopter operation, but especially for police aircraft because the mission equipment is so heavy.
[Before someone accuses me of being incorrect, there is one police helicopter unit that does operate IFR, with IR pilots]
NVG - at the moment there is one unit that uses NVG for pilots, one that uses them for observers. Several more are in the process of moving to NVG. The CAA stance has changed a bit. They seem to be much more keen on them, than previously.
There are big practical difficulties to going IFR in some cases in the UK. Many Units operate in areas with little or no IFR letdowns (we aren't allowed to use GPS). Also police ops are fundamentally VMC, visual contact.
However, we do need the skills, currency, equipment, fuel etc. to be able to cope if we go inadvertent at night...........