My qt application (feedback and suggestions)

I'm have in the process of porting an application to qt and I'd like to also improve the usability by changing the interface design. This is probably the one last hurdle that's preventing me from finishing up the code.

My problem is this:

I have got a list of object each has properties. I'm looking for an approach that will let the user see the entire list and change individual properties.

Here is what I got so far.

http://www.sassociations.net/cfrankb.../snapshot8.png

Another idea was to add tabs to the mainframe of the application, one for levels, another for objects, graphics and sounds. I'd appreciate another opinion on this.

I need a way to make this simpler. Ideas, suggestions, feedback welcome. :D