Somewhere along the road you wrote
Grub is something I could use some help with. My understanding is that each distro may install its own custom grub, like Mint. Both made themselves the default and applied their branding. Is it easy to make my own grub, or determine which I prefer?
About right (BTW don't use a separate boot partition if you intend to have a few distros - you can't share it)
Each distro installs its own /boot and thus grub. A well behaved distro (and in my experience there are not many outside the Ubuntu family in this respect) lists all the other distros too.
Now, you can use, say, Min's grub and have a default boot into Fedora or PCLOS or....
To understand this you need to know a bit about grub
It's divided into stage 1, 1.5 and 2
Stage one must (well you could chainload from something else) be in the MBR and can refer to any grub you find on the disk... (and chainload Windows)
And MBR is just the first 512 bytes of the disk...
This is what you choose when you repair grubhttp://www.linuxmint.com/wiki/index.php ... _your_grub
Then you can edit menu.lst to your liking and get the Mint grub booting something else by default