"So if Scotland becomes independent do we in England get our money back? With interest of course."

You've put a very anglicised slant on history. By the end of the 17thC the Scots had come to the conclusion that the semi-union brought about by the Union of the Crowns simply worked against them. They had by association with England lost much of their trade and were still being denied full access to the emerging English empire. They realised that either a fuller union or a seperation was needed to thrive and the Scottish Parliament initially looked to the latter option. Act of Security was passed by the Scottish Parliament in 1704 and set out that on the death of Queen Anne Scotland would choose a different monarch to England. The following year the English parliament passed the Alien Act. Basically if the Scots did not accept the Hanovarian succession then there would be virtually a complete trade embargo imposed on Scotland and the property of Scots in England could be confiscated. The Scottish aristos were blackmailed and bullied into eventually accepting the succession and union. Any payments were seen as much as compensation (for the losses at Darien) as they were bribes. Neither the Scottish or English populace at large were enthusiastic about union. What happens in the here and now is about the here and now and not about some imaginery debt from 300 years ago. Be it a positive or negative Scotland more than played its part in the creation and running of the British Empire and in the turning of GB plc into the world economic power house it became in the 19thC. Likewise Scots know that they contributed much more than economically. Visit the National Memorial in Edinburgh Castle and you'll see the names of the Scots who fell in both wars. 100,000 in WWI and 50,000 in WWII. By % of population it is way in excess of what it should be. What price would you put on that sacrifice?