First, I'm still a novice in editing so I'm sorry for the ignorance in the field but I could use a life savior. :P
I edited an hour long fashion show video in FCP7 in H.264 (i know i messed up really really bad) and every time i export it to a QT movie it gets pixelated sometimes and on every dissolve it becomes green or it simply skips. I usually edit 10 minute videos and didn't have this problem before, although it took me hours to convert and export correctly.
1. Should i use QT conversion when exporting so the green sections and pixelations don't appear?
2. I've read of using Media Manager to change H.264 to ProRes.... but its an hour long video. Do i have to change the original clips and then the sequence, or the other way around?
Try changing the sequence settings to prores 433, saying a bruccha, then re-rendering. You NEVER edit h.264 natively in FCP7. You must always pre-convert it to a format FCP7 understands first, then import that.
Once your re-rendered footage works out (and it might not), THEN you can export s h.264 if you need to.
FCPX handles all this for you int he background, I recommend it.