There is certainly room, as per my post on the previous page, Wales and Scotland have vast connected areas for these animals to survive. Hill farming and the acceptance that there is a yearly unaccounted for livestock loss anyway creates a very different environment to what you typically find in lowland country areas, with ample food for large predators. There is no outcry against predators in these upland areas because animal losses through falling/drowning/illness and rustling are usually a bigger problem. Large areas of dense native woodland flank the wilderness areas for cover.
I think the phrase 'big cat' is a generic term people are using for any cat larger than a house cat. Some reports hint at specific species, others are more vague. It must be remembered that often these sightings take place for only a split second, hence why all sorts of other animals can be misconstrued as 'big cats'.
I have not read much about the censorship of reports, perhaps someone could elaborate.
I would certainly report any animal that I believe is dangerous, I take frequent walks on the moors and I wouldn't wish anyone doing the same to encounter anything that can do them harm if it could have been prevented. The caveat is I would require some certainty of what I saw. I reported both large dogs that entered my property but never heard anything more. They left and presumably crossed the moor(10 miles in any direction - only way to get to/away from my property).
I think the key thing with this is that people who live in other less remote areas see how impractical it would be for these animals to exist in their own area and dismiss it out of hand. Spend a year in the isolated Welsh or Scottish mountains and you will see how easy it would be for a predator to both survive and exist undetected.
