Adobe's track record for bugs recently is reminiscent of MS a decade ago with the 9x/ME debacles.
Plenty of other PDF viewers around, as mentioned by others, Foxit probably being one of the most popular although I found recent versions a little too ad-ridden so I've switched to one called Sumatra.
Making PDFs? Use Open Office or again, one of the other many free formats.
As to Flash, I think it has a variety of patents attached so Adobe may sit down hard on any competitive player in the US. May be wrong on that though. I do know they're extremely hostile to the idea of a 3rd party player.
Easiest method of stopping Flash buggering your system is to use a flashblock extension of some sort with your favourite browser (I know both FF and Chrome support it).