That's kind of how I think about it as well, highers are basically just as-level because they're done at similar ages but the more you think about it the more complicated it becomes and they're not really the same in the end so better not to dwell on it

) .
I felt like when I moved, national 5s were easier than GCSEs so I did quite well in them. I ended up underestimating the higher courses because they're definitely a big jump from national 5s , and advanced highers even more so.
Maths might still be something useful to do (higher i mean, us adv higher maths ppl are a bit insane lol) but if you've already done AS-level then it should be fine I think, but double check once you start here. In the beginning you'll certainly have the chance to play about with your subjects, picking more or dropping others so you understand what's needed of them and whether you like them or not and can manage the workload etc. Tbh I quite like memorising sort of subjects too like biology it's just so much easier 🥹 but I really do enjoy maths now because there's no silly tricks involved like in chemistry for example where a rule might not apply in every situation so you have to learn exceptions and it's very tiring, maths might be tricky to understand at first but the only thing you need for that subject is practice and nothing else!
Yes, I felt like when I first started I didn't mind the younger students but now in s6 I realise how older we've all become and the small ones are getting crazier by the day oml 😭🙏 it can definitely be frustrating sometimes having to share the building with them because some of them have no respect at all, they can be quite rude - and funny - but it's certainly not a big problem and you may or may not get used to it. It'll only be for a year though so enjoy the noise while it lasts!
Crashing is something that I think is really good to be honest, even though I didn't crash any subjects myself but it's definitely useful especially if you decide against a career or just want to try something new, and it's not uncommon here either.
Hopefully they allow you to do three sciences, in s4 I did three sciences; I would go to my bio and chem classes and I learnt physics myself purely because I love the subject and the timetables didn't allow it (biology and physics were on at the same time). I think there's someone else in my school now who did the same but is also studying the three sciences at higher level (obviously one science off-timetable) which I didn't do because it was eating too much time and I'd have risked all my grades and everyone advised me against it and for some reason I listened (regrets) 🤪. But if you really really want to, beg for it!!
S6, i was looking forward to it honestly but it seems so much worse than s5 😅 because of having to do things outside of school like the UCAT, interviews, experiences etc etc etc.
Advanced biology and chem (and maybe other subjects too though I'm not entirely sure) have components called projects which you could say is kind of like an EPQ that's integrated into the subject itself rather than being its own separate qualification? They're worth quite a chunk of the overall grade and they take up a lot of time too compared to the assignments of highers, which is another reason s5 was better :// the good thing abt s6 tho is that if you pick less than 5 subjects you get free periods 🍃
becoming a surgeon is quite an aspiration, honestly I'm not planning to be a surgeon myself at the moment i'll decide later on 🥹 I hope you manage to achieve your dreams in that regard then, make sure to study smart and get good grades!!
np, and yes why not 🥳