OK - I got an email back from tech support on this issue.
1. It is intended behavior not to be able to edit midi clips in Event List for clips that were created with Step Sequencer. (This should be noted somewhere in the documentation, but to the best of my knowledge is not. I will submit a feature request or whatever they call it).
2. There IS already a bug logged where if a midi clip is created using a drum map, it messes up opening up the clip again in Step Sequencer. If I had been able to edit in SS, I never would have tried using Event List - but at least they are aware of this issue - and knowing it is caused by using the drum map within Step Sequencer, I now know how to continue without having this issue - just don't use a drum map with SS. The email indicated but did not commit to - a potential for a fix in the next round of maintenance. Hope it is there, but knowing how to avoid the issue in the meantime is fine - THANKS Cakewalk folks :)
And I did indeed bounce to a clip and it disconnected the events in the track from Step Sequencer, and I can now edit to my hearts content using Event List or PRV.
Sooooooooooo, I am back on track, and that's cool. I already fixed the errant events in my drum track - so onward and sideways :)
Bob Bone