UFS MBR, UFS & Separate /boot Partition


I'm trying to install FreeBSD 10.3 on my old desktop (HP XW6600). As far as I know this motherboard for this desktop doesn't support booting from USB with GPT partition (Please correct me if I'm wrong). Before I perform the actual deployment to this desktop, I'm using Virtualbox.

My Requirement(s):
  1. Use MBR Partition.
  2. UFS (No Encryption).
  3. Separate /boot Partition.
I have tried using FreeBSD install to perform installation, but for my learning purposes, I want to perform manual installation.

I found a great tutorial online http://www.wonkity.com/~wblock/docs/html/disksetup.html
Section: "The Old Standard: MBR"

Virtualbox Setup:
  1. ATA Controller (ada0) [50GB].
  2. UEFI is Disabled (Using BIOS).
Problem: After setup and installation, I get "No Operating System Installed" from Virtualbox.

Here are the step(s) I took (boot virtual machine from FreeBSD AMD64 iso [no UEFI]):
gpart create -s mbr ada0
gpart bootcode -b /boot/mbr ada0

gpart add -t freebsd ada0
gpart set -a active -i 1 ada0

gpart create -s bsd ada0s1
gpart bootcode -b /boot/boot ada0s1

gpart add -t freebsd-ufs  -a 4k -s 1g   ada0s1
gpart add -t freebsd-ufs  -a 4k -s 3g   ada0s1
gpart add -t freebsd-ufs  -a 4k -s 4g   ada0s1
gpart add -t freebsd-ufs  -a 4k         ada0s1

newfs -O2 -U -n -f 4096 -L bootfs /dev/ada0s1a
newfs -O2 -U -n -f 4096 -L rootfs /dev/ada0s1b
newfs -O2 -U -n -f 4096 -L varfs  /dev/ada0s1d
newfs -O2 -U -n -f 4096 -L usrfs  /dev/ada0s1e

[*]Mount the Filesystem into [FILE]/tmp[/FILE]
[*]Extract [FILE]txz[/FILE] files from  [FILE]/usr/freebsd-dist[/FILE]
[*]Change [FILE]root[/FILE] password
[*]Add User [CMD]adduser[/CMD]
[*]Setup timezone [CMD]tzsetup[/CMD]
[*]Create [FILE]/etc/fstab[/FILE]

My /etc/fstab:
/dev/ufs/rootfs    /        ufs    rw    0    0
/dev/ufs/bootfs    /boot    ufs    rw    0    0
/dev/ufs/varfs     /var     ufs    rw    0    0
/dev/ufs/usrfs     /usr     ufs    rw    0    0
devfs              /dev     devfs  rw    0    0
Thank in advance for help.