Edexcel AS/A Level Further Mathematics paper options

but school students have no choice in the matter

I think no universities require any combination other than the other. Some will encourage certain units for some courses, but school students have no choice in the matter, so I don't think any university actually asks for a specific topic.

You generally only do two of these, I think. You'd do core1+2, and then on top you can pick any 2 of the options (eg decision 1, further pure 1).

It would be in your best interest to choose whichever is easiest (to you). If you're studying physics as well, further mechanics 1 has a bunch of overlap, so taking that will be less work for you. For your other option, depends on subjects/interests really.

Incorrect, many schools offer students the choice of their modules, i.e. some classes pupils will vote etc.

Fair, correction that most* won't. School will decide based on teaching capacity/strengths/other reasons. I never had a choice in mine, for example. So unis generally won't require specific modules, since it'd be unfair to a large number of students.

I think no universities require any combination other than the other. Some will encourage certain units for some courses, but school students have no choice in the matter, so I don't think any university actually asks for a specific topic.

Many thanks, I think you’re right choose what I feel is easier and/or overlaps another subject.

Incorrect, many schools offer students the choice of their modules, i.e. some classes pupils will vote etc.