This may be long -sorry.
As I said above I came across the UP thread yesterday (toothache and scanning MN for distraction) and had a read. I realised that my parenting style was very similar and I am likely an UP. (I don't need a name for it and certainly don't like to name what I do).
I haven't always parented this way and it has come about as it is right for DS and I.
I was left as a single parent when DS was 13 months - abroad and alone. I had 2 jobs and limited time and always barked orders of getting dressed/ do this/that.
DS has always beeen a very compliant child and I was often praised on his behaviour.
We moved back to the UK when he was 22 months and of course he started the 'difficult phase'. My usual warning and consequence didn't appear to be working as he'd do it again and again. He accepted the punichment but it didn't stop him doing the crime iyswim.
So my Mum suggested smacking - I tried it
but tbh I never felt comfortable doing it and DS (of course!) didn't like it either. I stopped after I'd smacked him 3 times. (and yes they were calculated times
)
Then when he was 4.03 he started school. He had problems. Always getting into trouble and again repeat offending. It was a very hard time for me as up until then everyone said how well behaved he was, and also I saw him become very miserable.
One day he said to me 'I hate that Mrs X thinks I'm naughty, why am I a naughty boy mummy'
. He was 4.5 at the time.
SO.... I took a look at things and realised that maybe my parenting style of 'expecting' him to behave wasn't working and he needed guidence and help about how and why to behave. It took a year or so to get it right but I can honestly say its worked and I've not used (or needed) the naughty step for over a year and this years teacher says jow well behaved he is. 
DS is not perfect. But by explaining and most importantly listening we've got a far better and fun relationship.
For example: Before I would have said 'DS, put your trainers on' His reply of 'I don't want my trainers on' would have been met with 'I don't care I've told you to do it so do it'. Now I would say 'why not, we are going out you need shoes on'. DS will reply he wants to wear x shoes instead because...
With regards to the aeroplane and seatbelt - that doesn't seem like UP to me. I would have told DS why he had to wear it but would have enforced the rules and told him when it could be removed. Its about understanding.
I'm not going to announce myself as an UP - but as a parent trying their best. I agree with most of the principles but I get it wrong sometimes/ have a bad day and bark an order.