That's not totally true, but it IS the easiest way.
What's wrong about this? And what exactly are you referring to?
There are several disk images with partition tables somewhere
on the rockbox site that can be down loaded and copied to the
disk, but you will need Linux to do it.
This is not true. While it works best using linux dd is available for windows as well. You might not find any instructions for windows on the site though. It is still possible.
Since those images are for the 4 and 6 gb disk partition tables they won't help with a
CF conversion anyway.
This is not true. First, there are MBR files around for the 3G. Second, the important part is the firmware partition and it being part of the MBR. I upgraded my mini with a 32GB CF card a while ago, and to prepare the CF card I simply wrote the 4GB mini MBR to it, wrote the firmware (as described in the conversion wiki page). After that I simply removed the second (data) partition using fdisk and recreated it to use all available space on the card. Now finally create a filesystem and install Rockbox. Done.
Works flawlessly since several month, and the MBR files were useful for the conversion.