In Premiere CS6, both Prelude and Premiere, range markers (those with duration greater than zero) obscure any point markers (those with duration=0, the default). This is demonstrated at http://tv.adobe.com/watch/learn-premiere-pro-cs6/improved-markers-and-importing-from-prelu de/ , at around 04:42. This obscuration discourages use of range-markers.
Please could you reverse that situation, so that point markers instead overlay range markers. In fact, more generally, shorter-duration markers should overlay longer-duration markers. The idea is that the longer-duration markers would serve as useful background to the shorter-duration ones, and also of course this would reduce loss of information display.
How it would be useful in practice:
For example, when editing a presentation, it is useful to initially mark ranges covering periods such as Establishing, Main Talk, Question&Answer Session, Finale & Applause. Then on top of that to add shorter-duration markers for particular elements to be used or avoided. Then on top of that, add markers for point-events such as "camera jolt".
Better still (feature-request):
Ideally, markers should be considered as a special compound kind of track, a metadata track (after all, markers do get stored as metadata). This (compound) track could then be viewed either in collapsed mode (where it would look like a single track, hopefully with the overlay priorities as described bove) or in expanded mode (revealing some number of separate lanes, defined by user, of markers). Such lanes could be given meaning by the user e.g. Info, Vital-use, Nice-use-if-possible, Avoid, Ancillary (Clapperboard, Grey-Card, Color Charts etc.). Colors could be defined for each lane, to make them intuitive to people, at a glance.
Done, as two separate Feature Requests, one for marker display priority (short over long) and one for multi-lane marker (or metadata) tracks.
Until things change, you might give subclips a go. They're returned to proper functioning in CC7 where you see only the subclip range in the Source Monitor, but are free to extend or add transitions in the sequence.