I don't know what is is on the mbr. I think that before understanding how the Linux boot stages are, I need to install it in a working way. 
No. This is magically possible, but not practical.
You don't taste milk in the store before you buy, do you? You are looking at the technical specification: expiration date.
salvo gave good advice: use usb boot among others.
Linux mint is not so good at dual boot and it doesn't work if the hard disk is moved between sata connectors
Linux mint (and "grub" bootloader) not guilty that you change discs and do not tell him about it.
Bootloader "grub" knows only about what is written in its configuration file grub.cfg.
AROS grub has no differences in this regard.
Asus IPIBL-LB
aka
Benicia-GL8E (MicroATX), Intel G33 with ICH9R
Motherboard have Onboard RAID controller and 6 SATA (SATA-150 or SATA-300) connectors. This is typical for ASUS, but badly
fake SATA. I had a similar board P4C800E with onboard RAID. In practice, this means that a disk on one connector will be defined as sda1 (for example), and on the connector next to as sda14. You need to be careful about device names, or will have to spend endless time busting.
i can boot from it with the bios boot menu
BIOS configurable once so that it points to the disk where grub installed. Bootloader is used for everything and disks aren't dragged around.
if you need to change disks, then at least you don't need to change the disk where the bootloader is located.