should I clip/trim footage or use 0% opacity keyframes

Hi! This may be a stupidly obvious question but i'm wondering what would yield better/easier results. my project is a music video comprised of multiple scenes, band footage, and green screen shots.

For example I have drummer playing entire song, do I create clips of the scenes/frames I want to use in Premiere and sync to my audio. Or simply add multiple keyframes setting 0% opacity when I want to hide it in my AE compositions?

I'm thinking opacity would be easier for me to eventually sync with audio but i'm new at this so thought I'd ask. Thanks in advance

ps. currently using AE 6.5 going to CS3 next week, yeah!