Yes, you can both telnet and SSH into the Kindle with the USBNetwork hack. You can find it here:
https://www.mobileread.com/forums/showthread.php?t=88004
In normal reading mode, you can remove the horizontal margins by changing the setting in /system/com.amazon.ebook.booklet.reader/reader.pref file (enable view hidden files/folders on Windows), but not the bottom bar. For comics, you may consider using the picture viewer mode, which allows you to see images in full screen.