I can only tell you what I have learned about St. Andrews and we thought about all of those things.
Summer break is mid may to early September. No problem for my kid on the normal job front as she is highly in demand as an experienced lifeguard. If she gets research or something in the UK she is allowed to work full time in the summer on her visa.
She intends to go to grad or law school in the US and their admission rate in to US schools is quite good.