It's not a "secret" place, but I'll always believe the best place to watch the fireworks is on Main Street. However, we have watched them in Tomorrowland and saw Tinkerbell fly over our heads. My daughters thought that was great! We couldn't see the fireworks as well as Main Street, but my daughters always remember seeing Tinkerbell right above us!
As for California Grill, I also was not sure I would like the food. I thought it would be too fancy for us. But, I loved it! I just went with the flow and my husband and I had a really romantic dinner. I had the pork tenderloin and loved it! Good luck!