Hualingan installed

Hi there, I'm new to this forum and just installed a new Hualingan unit on my X5 E53 Navi screen no DSP old 17-pin connector. I can be of a help for those who have similar cars.
I'm having the following problem (discovered so far)
- Radio sometimes/some places works very good, sometimes do not catch any station. Changing the radio area does not make a difference. Why? Where did you connect radio antenna to?
- When I touch the MOVIE icon, and in order to locate the movies file, I press the file icon, but it refers me to the right SD (GPS) card. How can I choose the left SD card?
- In the volume settings, what is SUB?
- In the GPS FILE PATH page, there is a PK tick, what is this? I couldn't notice any difference when I tick/untick that red box?
- I can't read from my iPod. Is this because it's old type (model A1059) or because it's formatted as exFAT not FAT32?
- I tried to format my iPod, but laptop says "Windows unable to format". Is there a way I don't know?
- When I start my car, the unit shows some image (previously I chose from navigation images). How can I change this image e.g. put BMW logo that appears when DVD loads? Can I upload image from SD for example?

If you answer some questions I'll be very thankful