Dude, first of all, you are on the wrong place to ask. Here is a forum for NMT based players, to which your player doesn't belong. Your player is Realtek based( even though was made by Kaiboer), so have a look on Realtek based threads.
1: I don't understand what exactly do you want, you are supposed to go online directly from your player, you don't need a PC for that
2: why do you need to see it? If you really need it, just connect your PC to USB slave of your player. ( if it is NTFS you will see it immediately, if EXT3, then use google)
3 & 4: Do you need to upgrade or update your player, if no, then you don't need to think about those files and why "I can't open "EXTENTION INFO" in "SYSEM" of my player"
you can find some info about your player.