Doing 7 subjects in a year.

Short answer: no dont do it

Long answer: Not a single university in Britain will care if you do 7 subjects. Assuming youre in 6th year and are applying to uni: make sure that you get 5 A/B's at higher and try to get an A/B in the adv highers. So for example if you got AABCC last year at higher then do like 2 Highers and an adv higher and go for AAA leaving you with AAAAABCC. If you are in a school which makes you sit 5 subjects (like mine) then only focus on 3 of them to get AAA or whatever it is you need. 7 subjects is completely unnecessary, even top unis only want 5 highers and 3 adv.

If youre in 5th year then do the adv highers and 4 highers which you think are important/relevant. AAAAA inc an adv higher in 5th year will get you an unconditional at any scottish uni and you are pretty much guaranteed a conditionals for english unis assuming you do at least 1 more higher and an adv higher in 6th year.

I missed out on 4th year so I only have N5's which means I need to get all my Highers done this year. Edinburgh wants 3 Highers in 1 year with at least BBB and I need AAAA for the typical offer to get into my course. I'm doing 2 year Highers for geography and biology (universities don't like 2 year sittings) which means I need to get more Highers since sitting over 2 years means they want more subjects at A/B. In total I think it's about AAAABB that I need to get this year, or I will be shot down likely. I'm just doing the Advanced Higher for fun though so I may drop it.

I'm doing 6 H and 1AH not 7H. So I could only do 4H this year that way, and if I don't get all A's then I'll be screwed (especially since higher maths and Physics can become very busy)

yeah I would only need AAAA but if I don't get AAAA then I'm screwed. And I need to have 2 or more sciences to get entry since I want a science related course.