May I ask you an honest question then?
Many Englishmen would welcome a home team wining the world cup at some point be they Scottish, Welsh or English.
Do you really think most Scots would be cheering the English if they won?
As you pointed out, you cannot speak for your nation as a whole.
As for some of England being "up theirselves" I think many Scots feel that way because of their own inferiority complex dating back many hundreds of years.
In fairness, if I were a Scot I would probably feel the same. Being a subjugated nation for so many years is bound to breed dislike.
Though it always amuses me that if England is really so bad why do so many Scots wish to live and work here?