Wow, here comes the attacks on people for not agreeing with you.
You speak as if owning land is something more significant than an agreement between you and the government that you can do certain (and very limited) things on a patch of earth that they still own..... 'owning' land just means you have certain rights to prevent others from doing things there, though, that list is very short. try going too high or low on the patch of 'land' you own, try building something others find unsightly? You'll find the limits can happen fairly quickly.
Anyway, without insults.
"A trespass is a direct injury to a person, his property or land, committed directly and intentionally by the defendant"
The English tort law of trespass.
Now Scotland's different, in that people have a rather larger right to roam without damage.
But to walk upon your land and knock on your door, does not cause any 'injury' (the legal definition here, which is rather broad but there's no lasting anything in this case)
If done infrequently enough to not cause harassment, then there is no issue.
You saying you will inform them of a change doesn't mean anything. If I invite police to search my property for say a gun, then say I'll 'let them know if that changes', do you think my word is perfectly fine and trustworthy to make sure I don't have an unlicensed firearm in the future?
You say you hate people like me? Not sure why, I don't agree with the tv license, but if you don't like a law then campaign for it to be changed and/or support those that do. I just don't agree with people who decide the best way to deal with it is hide behind mis-information.