First off this talk of airmail rates for post is absolute garbage. There will always be a mail service so long as there's demand and there will always be trucks of mail driving across the border each night as there is now. The Royal Mail will be a private company long before any independence agreements.
Protecting oilfields from terrorists will continue exactly as it does now. There are no ships patrolling the North sea now and there wont be in the future. Also laurence, in case you didn't know there is oil of the English coast as well as very large gas fields.
Military bases will be maintained in all parts of the UK that are deemed to be strategically sited for the defence of those islands. Have you ever wondered who defends the Republic of Ireland? About nine thousand soldiers. One thousand sailors and eight hundred airmen using an array of small arms, light vehicles and fast patrol vessels. No nuclear. No aircraft carriers of frigates and a handful of fighter planes. Guess what? They've never been attacked except from England.
On the subject of wages, those you mention may well be earning less than those over here but thats more to do with the fact that people are in these positions are overpaid in this country. Four years ago a barman in Killarney earned 12 euro's an hour. Over twice what the same position earned in UK.
You can pick and choose little bit and pieces all you like to try and scaremonger but it would make sense to research your arguements before spouting off.
And finally, are you aware that, at the moment, Scotland is officially NOT in recession?