I may be wrong, I usually am...

but I believe you can only boot on primary drives, primary harddrive, primary
CD/DVD or FlashDrive, things like that.

For booting that is right but Im just talking about home only. Im creating a new
/boot, /, and /home and then linking to my old /home and calling it /data.

No, it should be fine. I have several home partitions on various drives and the
only one that is important is the one used by the distro you are in. The rest
can be mounted and used as needed.

The one caution is in permissions. Since as far as your distro is concerned that
person who created the initial home is not you. You may have to access it as
root or change the permissions to make it less of a hassle. You will likely need
to open Nautilus as su with 'gksu nautilus' or if you have one in System,
Administration then use it. You can also rename the initial home to data or
whatever from gparted; just unmount it first.