Hugh. As you say around 84% of rights of way in Scotland are "claimed". For this to be the case, evidence of use would be submitted through Scotways to the local authority, and if the authority agrees, this will be adopted as a right of way. It may then be signposted as such. This is, in general, sufficient. It keeps the cost of having a path designated low, as at this stage there is little if any legal involvement.
Let's say some time down the line the landowner makes moves to block the right of way or prevent users from accessing it. This may be out of an ignorance of the law. The local authority would contact the landowner and notify them of the legal status of the path, and that if they continue to block/deny access they will go to court. Should the landowner back down, this would then be classed as an "asserted" right of way.
If the landowner gets bolshie and decides to go to court, then it's up to the courts. If the landowner loses, the path is "vindicated", which is probably the strongest position to have. However it will only arrive at this position after a long process, and usually only because some has tried to prevent its use.
Vindicated, or any other right of way, still have an important role to play. With more and more land being developed for industrial or residential use, or for the likes of windfarms, the fact a right of way exists means that those rights must be considered and hopefully protected when planning new developments. One example would be if siting a wind turbine near a right of way, where the turbine may be re-sited to prevent walkers being injured by ice thrown from the blades in cold weather.
This is perhaps all a bit too detailed for a walkers handbook, and your paragraph regarding CROW may cloud things to the casual path user, as it really has no relevance to whether they can walk somewhere or not.