Welcome to the site! If I'm reading your response to Mark correctly, and you've been riding 30 miles per week for basically two years, that's only about 4K miles of total riding experience. That's not much. The suggestion to get out in an empty parking lot occasionally and spend about 15 minutes practicing slow speed turns and manuevers, panic braking, etc is excellent advice. Get to know the capabilities of both the bike and yourself, and the operation of the bike becomes so routine that you don't ever have to think about it...shifting, braking, turning at both low and high speeds, etc. I don't live in California, and have never been there, so lane splitting is not something I've ever done. I have traveled short distances on the shoulder of the freeway...very cautiously to get to the next exit ramp so that I could avoid sitting still in traffic. Even that makes me uncomfortable because people around here will get pissed at bikes for doing that. Trying to fit a 900lb bike between cars would be something I'd have to get used to, and I've been riding long enough to have thousands and thousands of miles under my belt. I could probably get used to splitting when traffic was more or less at a standstill, and people were obviously willing to let me go between them, but doing so at speed would make my azz pucker, big time.
No disrespect intended, but I think you need some more experience under your belt...do some 200+ mile rides in a day, if your schedule allows...the longer you're on the bike each time, the more familiar and comfortable you become with the whole experience. It may sound wierd, but you become "one" with the bike and your position in space becomes something you don't have to think about.