I'm choosing my A levels fairly soon was wondering how hard I would find, and how good these are: Maths, Physics, computing and chemistry. May end up even doing further maths instead of computing. Are these too much work do you reckon? I'm mainly on A*'s at the moment in GCSE. I've also been offered a chance to do an extended project (5000 word essay and a presentation etc) by the college I want to go to. Would that be a waste of time or actually worth doing. You get some UCAS points iirc. Any recommendations? I'm thinking about either comp-sci or mechanical or some other form of engineering at uni, providing I get there.
I don't want to pick stuff that will be too difficult for me, hence why I will more than likely avoid further maths.

How hard are chem and phys?
I'm currently in Year 12 having taken maths, further maths, physics, chemistry and biology, and I'm finding chemistry and biology much harder than further maths. Physics is primarily maths and remembering basic concepts, the rest can be done with a bit of common sense. Chemistry does require a fair bit of maths, but it's all easy stuff, however there is a lot more factual information to remember.
I would highly recommend taking further maths though, not only because I've found it my most enjoyable and interesting subject, and I absolutely love it, but because it'll help you immensely with normal maths. In our maths mock, the four of us taking further maths got A's, while the rest of the class got U's, there was nobody that was in between. It's hard to ascertain whether that is simply due to us being a lot better at maths generally or because we took further maths, but regardless the two subjects do tie in a lot, and I'd say that taking physics, maths and further maths together is more like taking 2 subjects than 3.
It'd be good to know how good your maths is though before taking further maths, it's an enormous step up over GCSE, and unless you completely breezed maths with guaranteed A*'s, I don't think I could recommend it. Those same people that were getting U's in AS maths got A's and A*'s in GCSE, so the step up to further maths is even greater. Look at what modules are involved in your A-level too, our f.maths consists of Decision 1 and 2, and Further Pure 1. If your working with algebra and ability to look beyond literal numbers and more at concepts isn't top notch, the pure part is probably what you'd struggle with. Decision 1 is just glorified dot-to-dots, number sorting and remembering algorithms, and the decision 2 we're currently learning is simply expanding on that, so if your memory is good that wouldn't be too hard.
As for chemistry, it's my personally most worrisome subject, seeing as how I need an A or A* at A2 to go into medicine, especially at cambridge as I'm hoping. However, so far I seem to be making it. My recent ISA came out with me getting the only A in the class (although that is taking last year's grade boundaries, which are likely to be lower this year), and my mocks have all come out with A's. I get my result of the last exam in march, so I'm praying that's an A too

In terms of difficulty, we're learning a new topic every lesson or two, compared to every week at GCSE, which certainly makes the amount to remember more, but it isn't that much more difficult. You need to have a good grasp of the basic concepts behind *why* molecules and atoms act the way they do - e.g. bonding, how phase changes are different at different areas of the periodic table, ionisation, how acidity and alkalinity actually work, etc. It also helps to have some common sense when it comes to rearranging equations, and calculating moles. Obviously a 1mol/dm^3 solution isn't going to give you 0.001 moles when you have 1000cm^3, which from what I've observed, seems to be the main kind of error that people make.
Physics - easier than chemistry, at least personally. As said earlier, it's more maths based than chemistry, and the majority of it revolves around rearranging equations and again, common sense. There is a bit of information to be remembered, but most of it you can still figure out from common sense. The sub atomic particles for example. The exam papers will usually ask you to complete a reaction, which I personally found impossible to remember simply from knowing all the reactions. Instead, I thought it was easier to deduce the values of strangeness, baryon number, etc from common sense, and then work out the reaction by knowing that they all have to be observed. My memory is awful, so physics is certainly more "open" to learn and recall how suits you best, rather than just drilling information into your head like biology and chemistry.