Hi RH CC,
First of all, thanks for your thoughtful post. I took a look at your issues.
Just started using subclips in an interview project and have run into similar problems as well; my impression is that there seems to be a problem with the way Premiere is handling the in and out points of subclips and not being able to keep track of them accurately. The very first clip I tried to edit into a sequence (after marking ins and outs on the subclip) brought over the entire original clip into the sequence. Since then, marking ins and outs on the subclips and dropping them in a sequence has been working great.
My experience is that subclips edited reliably into the Timeline. I didn't have the experience where the first subclip was the entire length of the master clip. If that happens again, please file a bug.
if I load a subclip into the source monitor, set new in and out points, then load a different subclip in the source monitor and do the same, then return back to the previous clip, the in and out points are gone (very frustrating when trying to compare two different takes).
Good catch. I could reproduce that behavior. Could you file a bug report on that?
Thanks,
Kevin