It is a bit difficult for me to check for this because I have never seen grub4dos so I don't know how it works and also I am using efi booting which alters things. However looking at your menu.lst it appears that grub4dos might be looking in the wrong place.
title Find Grub2\nBoot up grub2 if installed
find --set-root --ignore-floppies --ignore-cd /boot/grub/core.img
Manjaro does not keep core.img in that location it is stored in the folder /boot/grub/x86_64-efi on my system, on yours you should probably remove the -efi part from the end UNLESS you are using 32bit in which case it would be different, just have a look, I don't have any 32 bit versions so I can't check for myself. So basically if you found out where core.img really is and alter the menu.lst entry to the correct address it might work, I don't know for sure though. Your other alternatives would be to install grub-legacy into Manjaro or bite the bullet and face up to the fact that we are stuck with grub2 whether we like it or not and just move on - I guarantee I hate grub2 every bit as much as you do, but I have had to do it !