I am not an iPhone user, but if what you have described above are problems that a significant number of iPhone users face, then I am pretty surprised/disappointed.
All of these would be hampering user experience ( something Apple excels at ) irrespective of whether the user is a casual one or a heavy one.
Also, if these problems are easily reproducible and quite prevalent, isn't Apple solving these in upcoming upgrades? In other words, they must be getting some kind of feedback/bug-reports and these problems should surely have to be part of that.