Thanks a lot!
Following your link I found that list here scirra(dot)com/forum/c2-plugins-and-behaviors-list_t65170 (your topic actually) and, just with a quick look, I'm pretty sure I recognize at least some behaviours from the steam free version, such as Turret and zig zag, which makes me think there's probably many that are already in the steam version.
It seems that list was posted in 2011, is it being updated via edits when there's new ones to stay up to date? (If so, I could just install them all and I'd be sure to have all the ones steam has).
EDIT: sorry for the "link", I'm not allowed to post links yet.
EDIT2: hum, okay, maybe I'm mistaking about them being already in (weird, then what are the other turret and zig zag behaviours that are already in? and then why make a plug-in..), but my question about -- if the list I linked is up to date still stands. =)