3. The last time I was in Glasgow it was patently dry (not even damp) yet the ATIS was reporting WET WET WET. No, I was told, it was wet. So there is a difference between my WET and ATC's wet. It's not a big deal, I ignored the WET bit but I shouldn't have to do this in the UK.
This is an exceprt from the UK Manual of Air Traffic Services Part 1:
Unofficial Observations
Pilots of aircraft may report, or observations from the control tower may indicate, that the amount of water present or runway surface condition is different from that being reported. Under no circumstances are controllers to pass to pilots information that suggests that the runway surface condition is better than the official report. However, when a pilot’s report or an observation from the control tower indicates a worse runway surface condition this information is to be passed and identified as such (see Appendix E).
It is very clear that ATC are not allowed to report anything better than the official report from the Aerodrome Authority. In order to change this report the AA will need to inspect the runway, even though ATC and pilots can see that the runway is dry/dry/dry. So your question should really be why the runway wasn't inspected more recently/frequently.