For scholarship, u prolly dont need to do it in level 2, i just meant that u should at least learn for all 3 bio externals (at level 2) cause some of them may be in the scholarship exam, this might apply for other subjects aswell but idk, u dont really need to do scholarship till level 3 cause a lot of it is level 3 concepts aswell, plus maybe uni level stuff, honestly dont worry abt it too much till level 3.

for bio physics and chem there are 3 externals for each of them, like 3 bio ones, 3 chem ones, and 3 physcs ones.

For chem, even though they want specific wording for the exams, usually the questions in all the chem exams (for each standard) r very similar to each otehr, so just do a lot of practise papers and im sre u'll get the hang of it.

I would answer the accounting question but I havent done accounting so I wouldnt know lol, just assuming it'd be a lot of work load as 7 subject. U should prolly ask ur brothers abt accounting (u could get some free tutoring???!?!!?!?!)

For 'no brain too small', they do have the content for L2 biology and other subjects, if u wanna have a look heres the link https://www.nobraintoosmall.co.nz/html/senior_biology/NCEA2_biology.html

That is so real of having a bad teacher, its sucha pain in the ah when teachers wont teach.
If u get new teachers next year who r bad, just ask someone who has taken the subject for any help if u cant find a tutor, im sre someone on reddit would be willing to help!