Shakespeare’s Prospero a real magician?

I just found this interesting Shakespearean conspiracy theory as reported by Neil Reynolds in The Globe and Mail:

"The secret knowledge is all right there in The Tempest, Shakespeare’s story of a marooned magician who conjures a shipwreck to confront and confound his antagonists...

Here (maybe) is the astonishing truth: Shakespeare’s Prospero was a 16th-century nobleman, pagan in practice, who conjured a series of storms at sea to take the life of Scotland’s King James VI – who (as England’s King James I) sat in the audience for the premiere of The Tempest in 1611. The historical sorcerer: Francis Stewart, fifth Earl of Bothwell, Lord High Admiral of Scotland and cousin of the king."  ...(Cont.)...