Some of the waters in all honesty for £24 a year aint that bad with some cracking carp in them. Yes i have done a lot of time on Trench and had some really nice fish with plenty of 20s to go at. The old scaley fish you are on about did get relocated to a retirement water for it's own good as it got caught about 6 times in a couple of weeks and was dropped on the rocks which did it the world of good. Wouldn't normally agree with moving it but it was done for its own good. It lasted a few more years having a peaceful existance until i found it dead about 5 years ago. I have never had any trouble with my van while fishing Trench which i have done a lot these last few years just park on the pub carpark. Some stunning looking scaley mirrors and big commons in there at the moment.
Still lots of crays in the water and plenty on Tench we have had them to doubles while carping.
The pool at Horsehay you are on about is Simpsons pool, not supossed to be any fishing and to be honest there are only two fishable spots on the pool but yes their are some very big carp in the water which do like a mixer The pool in the village is the one full of bream but it does have a few carp in it.
The pool up part the golf course we used to fish for Rudd and Roach many many years ago never had any of the carp though.
Your point about the North Shropshire waters and the likes of Merrington is a fair one but the big problem is that most anglers just dont have access to those waters and in most likelyhood never will so they have to make the most of what is avaiable locally. For £24 quid a year you have access to carp over 30lb in 3 or 4 waters ie the Blue, Trench, Middle which has done a 32lb this year and some whackers in the Severn and maybe one or two surprises in other waters and lets be honest that aint bad value.
Jez