• Which of Bus Studies, Economics or English would be more 'highly regarded' (if at all) by uni admissions?
I'm no expert, others will be better qualified to answer but my 50 cents. Economics and English both highly regarded. I believe business studies may be slightly less so (in terms of academic uni applications).
• If students are strong in English and Maths, would English be a more enjoyable subject compared with Economics e.g.?
Not necessarily. I think economics can be a really interesting subject for many. Real life case studies; applied mathematics; even philosophy. English is great too if you love reading but some find the reading of Shakespeare etc, long essays etc. onerous tasks. What are your child's real passions?
• Of course A-levels are a real step up but, which of the following would you regard being the biggest step up if you did them at GCSE: Biology, Chemistry, DT, English, French, German, Latin, Maths, Physics?
Not really sure on the last question but overall I think you'd do well to get a couple of uni brochures/careers books and get a sense of longer term goals. This will help to give an idea of best for subjects/which not to drop. For, example to study psychology you do not need maths a level but I think it makes it a lot easier for students at university if they do have it.
If they want to be an engineer: Maths, Further Maths, Physics, chemistry etc would be most valuable; A banker: maths, further maths or computing, economics, a language maybe; a lawyer: English would be a good one; a nurse: chemistry, biology; marketing: English, maths and economics/business studies or psychology maybe. Psychology: maths, psychology, biology. Do they want a well paid business career or a caring/giving back, rewarding but possibly less well paid, career, or a creative career, practical career etc etc.
I believe the sciences can be made easier by doing more due to the overlap. My school advised to do chemistry as the central science to add biology/physics to