I think the issue is deeper than you think. You can actually edit any of the values in a part in a PCB. You have to open the part (and own it) to make changes.) you can see this if you Click on the ... of the part, you will see that the Add menu item is disabled. All of these items should be show as disabled and not allow editing.

Another quick test is to delete and item, like on of the lines. It will be deleted, but when you exit the project and come on again the item will be present again.

Same is true of changing the position of some of the text.