A market app called Power Control Plus (paid app) allows you to add customized control widgets to the notification bar. There might bea free app that does this as well but if so I'm not aware of it. The only difference is that the Power Control Plus widget will always be placed as the last item in the notification bar compared to it being placed first as in CM6.
And when it comes to using the volume buttons to skip tracks, PowerAmp (not free...actually kind of pricey but worth the cost IMO) I know allows you to place a PowerAmp widget on the lockscreen. Let me go check and see what the volum rocker does and I'll post right back with the results.
Edit: Ok, it appears as if the volume rocker controls, well, the volume lol. I wasn't able to find anywhere in the settings where I could change this either. Damn, I thought I was going to be able to answer both your questions. At least the powwer control widget works

... well if you don't mind spending a little bit. It's really customizable with loads of extended controls, and definately worth chucking some loose change over to the dev for.