Tristan and Isolde

Seeing as Questions one and two go hand in hand, I'll answer them with the same response.

Magic, scifi and all that mystical stuff just isn't realistic. I'm guessing the main reason that the movie starts with a battle scene in an almost historical relevant situation or that the movie is completely devoid of magic is due to the screed writers and studio heads wanting a modern day audience connecting with the characters.

Elixirs, dragons, and dwarfs might alienate people and draw in a more 'nerdy' crowd. We need to dig into the world of studio politics and marketing. This movie, in it's basic form, is a basic studio produced romantic drama.

This gives us almost a whole new story, yet the characters are still loyal to their personalities. Isolde is the one who suggests meeting up and that Tristan not give up on love. Tristan is conflicted with his loyalty to Mark and his love for Isolde and wishes to stop the affair more then once.

All in all, the changes were made for marketing and really, if you think about it, time.