I think P mode does take the aperture setting into consideration, it will use the set aperture if a matching shutter speed is available. If set at F/22 it will choose the highest aperture that fits the minimum shutter speed, ie prefer more depth of field using the lowest set shutter speed (default 1/60 I think, you can change this). And if set at F/2 it will choose the lowest aperture value that fits the top speed of 1/250, ie choose the lowest aperture (ie least depth of field, most bokeh) without blowing out the highlights. So you can maximize or minimize depth of field but still shoot automatically in P mode by choosing the extremes on the aperture dial.
I don't know how common it is, but my AF has electric contact issues in the shutter button. This can cause problems if using half press to set focus and then recompose, on pressing through to trip the shutter mine would sometimes refocus but now probably on a different subject and loose focus on the original subject.
It's not always obvious, if I remember correctly, to test set slow shutter speed, say 1/2 second (no film in camera preferably), half press on close focus subject, recompose to a far focus subject, press through and see if the barel moved before or after the shutter noise is done.
This is a video on how to repair/improve
I did do this and although a bit scary it wasn't that difficult, and I did improve the shutter button action a lot but not perfect.
It's a very cool camera, but in the end I went for a Minolta CLE - not much bigger and more flexible. I still have the Hexar AF and I've been meaning to get a new battery and take the Hexar out for a spin. Given that 95% of the time I use the CLE with the 40mm lens so I'm not using the 'flexibility' that I thought I wanted all that much.