No, that is not normal. What kind of external HD are you using? It's possible that your PS3 only recognizes it as USB 1. I would cancel and try the backup to the internal HD. If you see the same speed then something is wrong with your backup manager. Try MultiMan.
No you shouldn't, it will just write over the necessary files. If you decide to go with MultiMan, you can move your backups out to hdd_0\GAMES and then you dont have to worry about updates overwriting your backups. If you are worried about OM though, I would use an FTP program to move your GAMEZ folder temporarily just to be safe.
Hi, it's due to the number of small files on the game i had the same trouble with destroy all humans it took over 2 hours to back up and is only 17gb and backed up 40 gb games in less than half the time ie god of war 3 with same back up manager just be patient it will work in the end also if you delete the game it takes just as long to delete due to the number of files.