I didn't find any custom roms, so my question is:

I've used 800w for my local carrier (which doesn't support Sprint apps). So I don't need Software Store, Sprint Nav and Sprint TV.

Is there any way to remove these apps from phone?

Second one about memory for programs:

When I start WM Player and connect my A2DP headset, free memory for programs is about 5 Mb. Is there any way to increse this number?