You could always give a couple of units of fast acting insulin at a party. It's difficult because you don't want to give mixed messages either. Sometimes I say have what you want within reason (of course at 7 he is on his own at parties) so long as you do a reading and have insulin on return. He has actually learnt to be quite good and not go crazy with the sweet stuff - quite hard for someone who loved his food and has a very sweet tooth - I think you just get less addicted as well if you don't have so much.
Also my ds has learnt how horrible he feels if he overdoes things.
Going for teas is a problem as well (again you won't be there yet) but have to be sure the parent doesn't mind and that they are comfortable with a child injecting etc. - so far though everyone has been fantastic.
Basal bolus is one long lasting insulin for overnight and through the day (we do at bedtime) - ours is levemir and then novorapid with each meal (and if you need extra). We originally started on 3 so he didn't have to inject at school, but moved to 4 over the summer when his control was really bad and I felt he was ready to do it at school. It means he can eat much more of what he wants and if he does go high then it's not for long. Not really a good idea for your ds until he is happier with the injections and probably a bit older.
Where abouts are you? We were in London originally where they were keener on more injections. Now we are in Gloucestershire which is not quite so "advanced" but friendlier, more personal team (and we can park in the car park!). Also our school is very small, so I am much happier with the environment for him.
I bet you are spending a lot of time reading labels at supermarkets - you realise what rubbish is in some stuff. It's no bad thing from that point of view and will make you all healthier.
I have put my ds down for the diabetic camp this summer in Southampton - he's never really been away from home before - not sure I'll be able to take him but I am sure it will do us all good to have a break and for him to get some independence.