Does iTunes sync Volume Adjustment and other per song settings?
Start and stop times do sync, as well as volume adjustments.

EQ settings sync as well. However, they only work under the following conditions:


You used a preset in iTunes (not custom EQ settings); and
You have EQ disabled on the phone.


As backwards as that second one sounds, if you EQ enabled on the phone, it uses that EQ setting and overrides the per-song EQ settings. If you have EQ disabled on the phone, it uses the per-song EQ settings.