Thanks to everyone for their input - we pretty much followed
@D4n 's advice:
Thirteen, which was probably a bit too much to ease them in gently, but 3/4 of us enjoyed it!
Hex freaked out my son a bit, so three of them headed for the exit before the ride bit.
The exit was beside the Cuckoo Cars Driving School, so my son did that whilst I was finishing in Hex (my daughter was too tall!)
We all then headed to the Congo River Rapids and Runaway Mine Train - everyone enjoyed both of those!
Lunch was at the Explorers Pizza and Pasta Buffet where there was, really surprisingly, no queue and was fairly good value for a captive theme park audience!
After lunch we did Duel, which I thought was fine, but the kids didn't like the things jumping out at them - I would have happily done that a few times given there was no queue, but once was enough for them.
Given the hesitation in some of the rides, we headed over to CBeebies land - we were outside the target audience age, but queued up for the Octonauts as that was their favourite programme a few years ago..... after 20 minutes they announced the ride was broken :-(. We therefore went to the Go Jetters ride which was really poorly managed - 3 staff, one of whom seemed to be doing nothing, one operating the ride, and the final one doing all the work. We could have got on a lot quicker if the queue had been better managed. Not really worth the wait, but we had to do something before....
Wicker Man! We got in the queue just before closing time, and it was still a 70 minute wait. To be honest we were all a bit apprehensive, but my wife and I tried not to show it so that the kids would go on it! In the end we all really enjoyed it! By the way, the
1973 Wicker Man film is on TV this week!
The biggest disappointment of the day was leaving the place, not because we didn't want to leave, but due to carnage in the car park! If they devoted a fraction of the resource to getting people out that they do to getting people in then it would be a lot better! It ended up taking about 45 minutes to get out.....
All in all a fun day out, but maybe we should have gone a few years ago when we had Merlin passes to experience the CBeebies Land, and spend more time this visit on the medium-thrill rides! Thanks again to everyone for their suggestions.