hmm that is weird, i have never experienced any of those problems in fact it has never crashed once for me, Its Limited in what it can do. but ive found it to be one of the more stable programs on my computer.
i never tried DE so i wouldnt know.
but its not like the reader even needs software to be used. You might want to look into Book Designer https://www.mobileread.com/forums/showthread.php?t=11786
I use it to convert all my books before putting it on the reader (it ussually only takes 10 minutes(to format, the actual conversion only takes seconds), and i do about 1 a day whenever i get a free moment.