Yes, you're able to totally automate effects/EQ etc.
Simply activate the read/write buttons in the top left corners of their windows, then any adjustments made during playback will be recorded. See the R/W buttons at the top left of this window?:
http://www.steinberg.net/typo3temp/pics/c68f83a595.jpg
Not in front of my SX3 right now, but you *should* be able to open up automation tracks for them too, so you can draw and tweak just as you do with fader automation. (I'm about 70% certain you can)...