First (before you import your media) you must go to preferences and make the right setting: export 1080i media to 1920x1080 (if you really want everything, but if you dont have enough space choose big, or something like that). Now import your movie, edit it and go to share,export movie. Make the right settings for the internet (you'll understand it, whenever it's compatible with youtube). Then for the 1080i you must export it through quicktime. Now this I never did, but i'm sure after using the help function and some searching on the internet, you'll figure out what the best settings are. Then burn them with iDVD. Remember to look at the settings before you begin importing. If you've got a blu-ray burner (an external one, from lg or lacie) you should use toast, it can burn with blu-ray. There you'll find better settings I believe.
