The Start10 settings that you're wanting to change are locked because you have a WindowBlinds theme loaded. If you apply the WindowBlinds "Default Theme" the Start10 settings will be unlocked.
If you want to use a Start10 button with a WB theme, you need to select the "Always use the OS start button..." option in WB:
As far as using the taskbar texture with a WB, I think you'd need to use his image to create a new texture within WB. I'm not seeing a way around it. Might take you a few passes to get it to look the way you want: