I have been to SFOG 7 times in the last 3 months. The last time being this past Saturday.
I would wait and feel out how busy they are before purchasing the Fast Pass. We have purchased it a couple of times this season and regretted it because the lines were not very long at all. This past Saturday they weren't that busy at all, but the Saturday before that they were packed. If they are busy, and you have the money, I would suggest buying the Platinum Flash Pass. The Saturday before last we still had 2 hour wait times on the bigger coaster with the regular Flash Pass.
I would recommend going straight to the Superman if you aren't buying a Flash Pass. The past few times I have been the longest line was at the Superman by far. However, the next longest line has been the Dare Devil Dive followed by Goliath. Both of the last two rides are located near other. If you do plan on doing this, I'd check out the park map online before going because the Superman is on the other side of the park, so you will want to be sure to know where you are going when you make you run for it.
The shortest lines every time have been at the Ninja, Scream Machine and Acrophobia. Acrophobia moves really fast no matter how long the line is, because each ride holds 30 people, and it's like a 45 second ride.
If you plan on stopping by the Monster Mansion expect a long line until about 7:30. It's a favorite for non thrill seekers and stays long the entire day!
Expect to get wet on Thunder River and Splash Waterfalls. It's pretty inevitable.
My recommended seats for the rides, include:
Superman: FRONT ROW ALL THE WAY! I will never ride anywhere but the front row again. If you are anywhere else you are staring the botto of somebody else's feet, and you get more of the flying feeling in the front row.
Goliath: BACK ROW! You get more airtime. I'd also suggest putting your feet up and well as your hands when you are going down.
Cyclone: ANYWHERE BUT THE BACK! This past Saturday when I was there we tried the back seat, and I will never again! The ride needs a little more retracking, and it pretty shaky right now.
Scream Machine: I'd suggest the front seat or any seat that does not have a wheel underneath it. It can pretty shaky in the very back and the back of any of the seperate cars.
Ninja: The second to last row or the very last row seem to be the least jarring.
Batman: FRONT ROW!
Mindbender: Front or Back row. I personally prefer the back row.
The Scorcher has really long load and unload time. I'm not sure why, but it has always taken longer than any other ride at the park. It's a great ride and worth the wait, but just expect to wait a little longer.
Just general information. The Sky Buckets load near the Acrophobia on one side and near Thunder River and Splash Waterfalls on the other side. The side with Thunder River is fairly close the Ninja, Scream Machine and Superman as well, if you go to the left when you are exiting the loading/unloading station.
Most of the food and drink places open around 11 and close around 8. This includes places that give free refills, so if you plan on grabbing one last refill for the road you might want to hit up a place about 7:50.
I don't have any food suggestions. I usually just grab chicken fingers from one of the many places that sell chicken fingers. We did each BBQ one time from Daddy'Os, but it wasn't really much to talk about. There is a Chinese and Mexican restaurant inside the park, but to be honest most of the time we bring our own lunch and go out the car and eat it. Also, there is a Wendy's right by the park that you could leave to eat at, and then return back into the park.
Acrophobia and Goliath are my two favorite rides in the park, by far. It's a fun park with a good bit today, but it can and will get hot pretty fast.
My 7 year old loves roller coasters more than your 7 year old! =P