Since you have a 7 year old...I would suggest bringing him something to be entertained during the first part of the universal studios tour. There is not much to "see" that would impress a 7 year old and he might get bored pretty quickly. This will soon end though and several little "thrills" will take place including the shark encounter and one with a very large gorilla.
Rides to skip...tough to say. I really don't think the Terminator 3-D show is for children. There is a lot of violence...guns, shooting..etc. If I would skip anything, that would be it. Other shows I would skip...the special effects stages and Van Helsing: Dracula Fortress.
The great part of going down to the lower lot early...you can do rides like The Mummy and Jurrasic Park more than once with no wait. We usually run back in line and do Jurrasic Park at least twice. It is a good ride.
Another helpful tip. Don't wait forever for shows. You can usually show up a few minutes before show time and get a decent seat if your party size is small (3-4 people).
The only attraction that seems to have huge waits in the upper lot is the Shrek 3-D show. I have found it to be a bit over-rated, but kids tend to love it. If you think your child will enjoy this one...stick out the line. The theater is huge, so it will go faster than it looks.
Not sure if you bought your tickets yet, but they are currently running a special if you buy your tickets online. Here it is...Not bad with the free meal and all.
1-Day Admission PLUS Free Child Ticket
Limited Time, Online-Only Offer: Buy a 1-Day General Admission ticket to Universal Studios Hollywood® and get a FREE child ticket (ages 3-11)!
Tickets include admission to Universal Studios Hollywood, including all rides, attractions, and shows.
This offer is not available at the park ticket booths.
Bonus! Purchase your tickets online and get over $100 in Universal Studios savings coupons. Coupons valid for use through December 31, 2005. Plus you'll get a coupon for a free kid's meal on CityWalk!
Tickets can be used any day through (and including) January 31, 2006.
NOTE: Number of free childrens tickets can not exceed number of paid tickets. To receive the free child's ticket, a quantity must be entered below in the field labeled "Free Child".
If you have any other specific questions, don't hesitate to ask. I am a frequent
Disneyland visitor and go to Universal quite often as well.
P.S - Check the opening times for the lower lot as soon as you get to the park. Somtimes it opens up to an hour after the rest of the park. If this is the case, do Shrek and then go to the lower lot as soon as it opens. You will basically hit all the major attractions that way!