I would like to bring this feature request under your attention again.
Mainly #1, the altitude graph using distance instead of speed.
When I plan my cycle trips I use http://www.routeyou.com (one of the best websites for creating your own route!).
When exporting a route from routeyou it includes the elevation:
<trkpt lon="4.854548" lat="52.383252">
<ele>4.000000</ele>
</trkpt>
It is really a shame that the graph in PE is not showing this, since it relies on the time for creating the graph.
PS: Now I have to use a tool like MyGPSFiles.com/app (Window » Toolbox » Time | Set Speed) to add a « fake » time field to the gpx file to get the elevation graph:
<trkpt lat="52.383252" lon="4.854548">
<ele>4</ele>
<time>2014-12-11T08:32:58Z</time>
</trkpt>