cas, I'm flattered I made your signature
Shortly after returning to the piano after a 30-year break, I suffered an illness and am going to be permanently on medication which, as a side affect, makes my hands shake fairly severely at times. With this came the realisation that I am never going to be able to play the piano as well as I would like.
While there's no such thing as a "free lunch", idiomatically speaking, where medicine is concerned, there are often several alternatives to any given medicine these days such that side effects experienced from one may be all but avoided with another if you'd like to consider consulting with your primary care physician about your hands.
I would still like to get as good as is possible under the circumstances but have decided that really now it makes more sense to just try and play for my own enjoyment, rather than slogging it our with theory/scales and the like (though I will still do some for warm up).
My only real interest is classical music. I tried the Alfred's AIO course but found I didn't really enjoy the pieces as they generally weren't the kind of music that I was very motivated by.
Regardless of the circumstances, you should always strive to play for your own enjoyment (who else's enjoyment would you be playing for
) and seek out music to play that you like. I'd imagine that after a period of time doing this, you'd actually get better anyways than if you spent the time "slogging away" at something you didn't like with less focus and effort, accordingly.
Any advice on good self-study books/programs etc that will help me develop my ability as much as possible but that are more focused on playing classical music for pleasure rather than to pass exams etc?
I would simply suggest a pragmatic approach of getting some music you like that you believe - or someone who's familiar with your capabilities believes - you can tackle and, like with learning to do anything new, looking for solutions to problems as you come across them. If you're not familiar with very much music, then you could ask or around or investigate some of Cas's suggestions.