I didn't do it at A-level but I am now doing a joint degree in Philosophy at university.
First thing to say is that philosophy is very varied. Most people think of it purely in terms of an essay subject (which it certainly can be) yet certain branches in analytic philosophy (computability theory, Logic) heavily resemble theoretical computer science and mathematical analysis so that's something to be a aware. These modules are quite heavily proof based and you would benefit hugely from having a good grasp of Maths (single / further are both good).
If they aren't your cup of tea, you can focus more on continental philosophy which is more essay based, although do note that most university courses will make you do a module in Logic.
I would argue that philosophy essays have a slightly higher emphasis of sound argument and logic over evidence based reasoning. I wouldn't say that this is necessarily harder than essays in History or social sciences but more that it is a differently style. There's a fair amount of rigour that you would have to develop in terms of argument, and studying philosophy is naturally very good at developing sound reasoning. Ethics is fantastic to learn about but is also a slightly different type of subject than conventional philosophy.
Regarding A-level, I'm not sure how 'well respected it is'. For a start, it's not in the 'facilitating subjects' listed for most universities. In fact when i was playing to university I was told explicitly to avoid taking philosophy A-level and just apply straight to a degree course. They said that they would rather me take another essay subject such as English Literature.
Honestly if I could recommend anything, I would say to do Maths A-level and English (Lit) A-level, perhaps history / FM if you are interested. They are both hugely useful subjects, great for Philosophy at Uni but also very diverse so you choose other things too.