if the teacher has been teaching for a while, so 5 or more years then it shows how good you are. defo pick spanish. as for politics, it's not really debating as most of it is writing and the debates you do have are usually overrun by liberalist/socialist students. but, if you want to pick politics then i'd swap psychology and do bio, chem, spanish and politics, as politics and spanish are both more respected than psychology. if you plan on doing psychology and/or neuroscience at university then psychology's really not required. if anything, spanish and politics show a wide breadth of subjects alongside your sciences. there's also loads of debates in second year of an a level language, all to do with the society, literature, politics, laws and foreign relations within that country.
tldr: pick bio, chem, spanish. i'd say pick politics instead of psych but it doesn't matter really because you've already got three facilitating subjects and neither politics or psychology is bad to take. if four is too much, just drop whatever you don't enjoy as much, whether that be biology, chemistry, spanish, politics or psychology.
hope this helped and if you need any more questions answered then please do ask me i'm active quite a lot rn

edit: only do four a levels if you can. pick four but if it's too much then drop one since your other grades are at risk. only pick 4 in my opinion if you can get A*A*A*A* or A*A*A*A as if you get A*A*AA or lower then you should have probs just picked three to get 3A*s. dk if that made sense so soz if it didn't