Been going through the same thing with my Galaxy Note 3. The one thing I know is at play is that when you add Dashclock to Widgetlocker, it is adding the home screen widget and not the lock screen widget, which explains part of the behavior. What I believe, but can't prove, is that somehow one program is recognized by the other and thus Dashclock is forced to run in expanded mode. I noted when trying different settings that you could see for a split second Dashclock showing up in the compressed mode, but then instantly pop up to fully expanded. That, plus the number of threads when searching on this issue where people are asking for the ability to run Dashclock fully expanded withing Widgetlocker leads me to believe it is the intended method of operation rather than a bug of some sort.
The closest I can come to what you and I seem to be looking for is to grab Better Dashclock. It's just a side version of Dashclock with additonal settings, but it should be compatible with all the different notification extensions. What you can do is add in all your extensions, and under each is a box that you check that will set the extension to "Always collapse". Then, in the Advanced menu, change the number of apps allowed to be collapsed from the default of three. You don't get the ability to pull down and see the expanded version, though that is more due to that feature being part of the lock screen version of the widget. Other downside is that Better Dashclock isn't free...
Going to try a different locker program and see if I can get somewhere with it instead of WidgetLocker....if I get anywhere I'll post it here.