now i don't know much about plugs in so i cannot exactly say. i do know they are add ons one can use but i know i did not download anything other than the basic browser.
flock is just another browser. it has a lot of gadgets and has a pretty full screen. but is not bad.
for how i download using mozilla...i just downloaded the software, installed it. i didn't do anythng special. i wouldn't know how anyway.
then when i access my account on youtube...select a video and when it begins to play....a small pop quickly appears top right of the video...is just click that and the video is copied to my computer in owner account is docs & settings.
does that help.