Have all the harder modules left in terms of content. Have people got 1/S and not done AFM?
No it isn't necessary. STEP I and II requires knowledge of C1-4 M1-2 S1-2, whereas STEP III requires FP1-3 and M2-4 ( I think, but do check the specification on the admission website).
You are better off focusing on getting a solid understanding of C1-4, M1-2, and then starting preparation for STEP. I've only just started C4, but will start preparing for STEP around December.
Have all the harder modules left in terms of content. Have people got 1/S and not done AFM?
AFM gives no benefits for getting into Uni or STEP. If you want you can cover all the applied topics for STEP III to improve your choice of questions, but there's no point in taking the exams. The higher stats modules are a minority sport. Assuming you're aiming at a Maths course extra stats will be of no help at Uni either.
Spend your time doing problem solving and getting your proofs right.
AFM gives no benefits for getting into Uni or STEP. If you want you can cover all the applied topics for STEP III to improve your choice of questions, but there's no point in taking the exams. The higher stats modules are a minority sport. Assuming you're aiming at a Maths course extra stats will be of no help at Uni either.
Spend your time doing problem solving and getting your proofs right.