Well I do Psychology (its amazing but a lot of work) sociology, English Lit/Lang and Business. I would say its easier to do business after doing it at GCSE, but Im currently on D/E and my friend who didnt take it is on B/C. Just put the work in and youll be okay.
But as another poster said, economics is meant to be good, and Psychology is amazing. I wouldnt take English personally, its a lot different than I thought it would be but I wouldnt say its horrible. Rest of your subjects are quite full on, my Biology friend seems to be always doing ISAs but she loves it. Its all up to you what you want to take but I wouldnt take on another heavy/confusing subject as you'll be stressed out.