Those are reasonable guesses, but as someone who was at Apple at the time (in developer relations, with Adobe/Macromedia among my developers), neither of those were Steve's primary annoyances with Flash. The actual annoyances were that the Flash runtime was (1) slow and (2) very crashy compared to the Windows version.
The former mattered because it created/reinforced a perception that Macs were slow. The latter mattered because it created/reinforced a perception that Macs were unstable, and it created a lot of expensive support calls. (For quite some time, the Flash runtime was the #1 cause of Mac crashes.)
There's more to this story (Adobe was threatening Apple on other fronts), but IMO Steve did the right thing by responding to a toxic partner in the way that he did.