Unless the policing methods are different in scotland, anyone who even drinks in the wrong pub will have been vidoed to death by the football liason officers. Simple communication between English and Scottish police will keep a lid on things.
Countryboy has already touched on ticket allocation, season ticket holders first, then share holders with x amount of shares, then share holders with less than x amount of shares, then half season ticket holders blah blah blah. By the time tickets get anywhere near general sale there's none left.
And for those who are ready to blame the English for something that hasn't happend yet, and you know who you are, Aldo, Countryboy, except for the odd Lewisham/Deptford civil war when was the last time you saw trouble at English club matches?