Anglicans during the reigns of the Charles's had a concept of the Royal Touch to heal disease. Was this part of the 1662 BCP or just a local custom?
There's no mention of the royal touch in the 1662 BCP, in anything that I have seen. As far as I know it was a middle-ages superstition. In the case of the 16-17th century Wars of Religion, it was reintroduced again, but this time mainly to establish the monarch's legitimacy more than anything else. Wikipedia- "The Glorious Revolution and subsequent abandonment of the idea of the divine right of kings rendered the royal touch unnecessary as means of proving monarch's legitimacy."
Yeah it was mainly a British and French thing and not really a purely Anglicans thing as such. Queen Anne was the last British monarch to practise it. Apparently it was removed from the Book of Common Prayer in 1732, as -1662 act of Uniformity and 1662 BoCP assent and consenters, here on this forum may want to ponder upon.
It has nothing to do with the Book of Common Prayer or even Anglicanism. It can be dated back to the Middle Ages when Western Christianity was Roman Catholicism. Anglicanism did not exist then. It was retained by some monarchs after the Reformation as it was about expressing a monarch's power and divine right to rule rather an expression of the Christian Faith.