I can answer those from our friends son, as we have chatted a lot about it:
Did he feel less 'independent' or in any way 'less important' than the boarders? No, though he feels he has to wake up quicker in the mornings, as he has to cycle in for 8am, rather than wander over to breakfast!
Did he prefer being a day pupil and why? In some ways he would love to board, but lives so close it really would be silly. On the other hand he also recognises that it's really nice to be able to keep in daily touch with his family, even if it is just for a quick update and a hug, so it is the best of both worlds.
How long did it take him to settle in? Err about 30 minutes! They are not allowed home at all apart from to sleep, for the first 2 weekends as there are lots of activities to ensure that boarders and day children alike settle in well, so school 7 days a week for 3 weeks!
Did he like the school? Yes, though like any children he has his ups and downs, but largely yes.
What time do they come home on Saturdays? After sports matches so between 4 and 6pm depending on whether the match is home and away. Pretty much everyone plays in a team, so this means everyone.
Is Saturday compulsory? Yes, lessons until 1pm, then sport.
Can day pupils invite boarders to come stay at the weekend? Yes, if there is parental permission they have a leave weekend every 3 weeks, and friends can be invited.