Just for starters:

• William Wallace was a member of the minor nobility, not a commoner.
• Medieval Scotsmen did not wear kilts. Indeed, even the kilt's predecessor, the belted plaid, dates only to the 16th century.
• Edward I did not institute right of the first night in Scotland.
• Isabelle of France was around 10 at the time of William Wallace's execution and didn't marry Edward II until two years later, when she was 12.