Im thinking of studying Psychology, Biology and Chemistry to A2 level and doing either Maths AS or Critical Thinking AS?
which would be more useful: maths or critical thinking?
Also would psychology be thought of highly by universities?
Maths is usually fairly well respected, as you have to be Numerate for Medicine - Ie For Drug calculations.
Critical thinking is a "New" A-Level, and medical education is full of people who are still in a historic era...
However critical thinking is very topical, especially for research / evidence evaluation. So I would actually contact some med schools and see what they think.