Question about how EasyBCD works with GRUB Legacy

Not having problems, just curious how things work.

Question 1: If I add an EasyBCD GRUB Legacy menu item by selecting a /boot partition, what are EasyBCD's requirements of that partition? Is it, for example, that /boot/grub/stage1 exist on that partition? Or is it somehow filesystem-independent where stage1 must be on the first sector of the selected partition?

Question 2: During a typical Linux install, for boot loader device I can choose (i) MBR (eg, sda) or (ii) "First sector of the boot partition” (eg, sda3). What's the difference? Is the only difference that (i) writes /boot/grub/stage1 to the MBR, and that otherwise both (i) and (ii) create identical copies of /boot (kernel data, grub conf, etc)? In both cases is stage1 written on the first sector of the /boot partition? If (i) was originally used and later the MBR was overwritten with Windows can I still select the /boot partition when adding a GRUB Legacy menu?

Info appreciated - thanks. My current setup: I'm using EasyBCD to dual boot Scientific Linux 6.5 and Windows 8.1 Pro on a 250GB SSD drive on a non-UEFI laptop.