Reclassifying the pavement as a "shared use path" (or vice versa) will make illegal behaviour legal (or vice versa) but will make not one jot of difference to whether the cyclist is being antisocial or not
Not sure about this, the example I'm thinking of is a line painted down a path that is alongside a main road and has a large number of private drives crossing it.
It creates a point at which a cyclist can easily come into contact with motorists.
On the particular path I'm thinking of, before the lines the cyclist would be illegally going down the path and when a motorist reversed from their drive they would easily cause a collision - the motorist would be expecting to encounter risk of collision
as they reached the curb. At this point it's the cyclist's fault and they would have no right getting in a huff about it.
After the lines, the roles are reversed and the onus is on the motorist to check each way immediately they leave their own property and then again at the curb.
There is no difference to safety of the path between the before and after stages but the behaviour of the cyclist is antisocial before and not after.
If councils can decide a path is safe just to justify their allocation of 'cycle paths' then I think the law about pavement cycling should be thrown out.