Ad 1:
I described this issue
here.
Ad 2:
I would very, very much hate to do that. There is as-is order in the category fields, the list of categories on the LC site is a closed set. The labels, on the other hand, are a real dump.
I even did an experiment once.
In my database of purchased e-books from various bookshops, I got more than 5,000 labels, often meaningless entries. Often in these labels there were typos, spelling mistakes, repeated titles, series, authors. I didn't even think about cleaning, preferring to remove all labels altogether.
You can add tags to the comments and then at least the search in the main window will work for all those strange labels.
I don't see a reasonable solution here.