1. To change the start logo make a Pictures folder on the root of your Micro Sd and put any jpg image. Try to resize your pictures to 800x480 but keep the aspect ratio. Insert the card in the unit go to settings and go to the upper right option. In there tap choose from sd. Wait till the pictures are loading then scrool to chose. If you have many options you can even preview before applying.
2. I don't know.