I know this is coming more than 7 years late, but no worries.
I watched this one several months ago and completely forgot about it until after I watched 'Blackbeard: Terror at Sea', also a UK TV movie, which was released one week after this one on the 10th September, 2006. I came looking for the cast of Terror at Sea and came across two conflicting films from the same month and year and realized I had in fact watched this one as well and wasn't so impressed.
This 'Pirates: The True Story of Blackbeard' truly is a 'mummers farce'(to borrow from Game of Thrones). Okay acting and costuming but terrible story line and characterization, that seems more fiction than anything, made for simple minded audiences to believe.
If you want more accuracy and less swashbuckling fiction type storyline I suggest looking at Blackbeard: Terror at Sea. It is narrated by Hands as if he wrote Blackbeards memoirs (not sure how accurate that is) and much better acting, with character focus and realistic storyline all round. It is more documentary style with the narration this way. Some of the music, especially at the beginning, is a little annoying with the narration, but maybe it was a poor audio version I watched, but when that drops off and they really get into the story.
Blackbeard is certainly a character you love to hate and hate to love.