Hi Novie!

1. Yes, you are considered as a settled person here in the UK.

2. I'm not sure about the flights. But when my nephew (he was 4 or 5 y.o. that time) went to Hong Kong with my parents and grandparents, I think his flight was on a 30 or 40% discount, even if he has a seat of his own too. Now, I'm not sure with flights going to UK. Maybe you can do a trial search on the airlines' sites to see if it is discounted.

Hope that helps