“Question1 - In order the player to remember the position there I left - do I HAVE TO copy thouse MP3 into Audiobooks folder?”
You could copy them to the podcasts folder instead if you want. If the files have audiobook or podcast as the genre, then they can be anywhere on the player and the player treats them as an audiobook or podcast. If the files are in the audiobooks or podcasts folder, the player will treat them as an audiobook or podcast no matter what the genre tag is.
“Question2 - If I do that, and then navigate to Audiobooks folder, I don see the file right away, I guess it show album names first. But I dont have any mp3 tags in those files. So it shows Unknown, How can I see the files directly, no the Albums in Audiobooks? Can I rearange this menu somhow?”
Use a tag editor such as the free program mp3Tag and fill in the tags.
http://www.mp3tag.de/en/
“Question3 - When I connect the player to a PC, a new drive letter is not added. Why? Instead I see the player in the list of devices and under “Computer” as external device attached. Why not drive letter? How can I set it to see drive letter for my player?”
It will assign a drive letter to the player and a separate drive letter to the card in it when the usb mode on the player is set to MSC. When it is set to MTP, the player is seen as a device. When set to autoconnect, the player might connect in MTP or MSC. If you don’t use protected files, then MSC is preferable. If you use protected files, you need MTP. Files transferred to the player in MTP won’t be seen on the player on your pc when connected in MSC and vice versa.
4"Question4 - When I see folders of my player, it seems that original music was put there under specific folder names like Artist folder, inside Album folder, and them the file itself. Is that necessary to do that? What if I just copy my folder “Classical Music” with a bunch of mp3s into Music folder of the player?"
You could do that and the player will sort them out as long as the tags are filled in properly. Transferring the files to the player in folders, or setting up folders on the player one for each album for example will help you keep things organized, and help you delete the music from the player that you want to get rid of much easier. It will also make it easy to see what music is on the player when you connect it to the pc. I usually transfer music to my players a folder at a time(or a folder containg several folders, each with an album)using Windows Explorer copy and paste,
“Question5 - And teh last one - can I manually re-arrange all the folders in the player, delete them, create new one I need? What whould be if I remove Audiobooks folder and create “History Books”, “Fantasy Books”, etc… ?? Will it still remember the position there I left listening the audiobook ?”
Don’t mess around with the folders the player creates, such as audiobooks or podcasts. If you delete them, the player will just recreate them anyway. It is best not to edit file tags on the player(and only possible to do so in MSC mode anyway). if you need to edit tags, do so on the copy on your pc, delete the copy on the player, then copy it to the player.