Is there any way to alter or change the default apps in these two docks?

i.e.:
MM/Alarm dock; 1)The weather app is wonderful in concept, location temp and forcast but, it takes days and days to update. Weather Channel.com is better but I can't seem to replace the default app.
2) Is there a way to force it to "auto" update. I put that in quotes because I have 'auto' toggled on and yet it doesn't actually work.

Car dock; The on screen nav app won't listen for voice while the blue arrow nav app has a wonderful voice recognition navagation app which I have put on the Home screen while in that dock. However, I want to delete/change the traffic(useless), nav, and search buttons and replace them.