First the script changed the video device driver from vesa to vboxvideo which gets me a maximum resolution of 1024x768. All other higher resolutions complained about "vrefresh out of range" or "hsync out of range". I do not understand how that can be given that I gave a wide range of hsync and vrefresh for my monitor. Finding little help from /var/log/Xorg.0.log, I decided to go back to my old vesa driver which at least gives be a slightly higher resolution of 1152x864. I was wishing the vbox driver could give me 1440x900 but that did not happen. Setting modelines also did not help so I gave up pretty quickly.
My next issue is that I am not able to mount my shared folder. I created a shared folder in VirtualBox > Settings. Which I should be able to mount from the guest OS using "mount -t vboxsf
There was another problem however. I cannot ssh from my master OS to the guest OS. After googling for a few minutes I found out that I need to set up port forwarding rules. Not sure how to do it from virtualbox. Another option is to use "Host attached" for the network instead of "NAT", but alas, I only have NAT option available in my VirtualBox beta3 for mac. Not sure how I can enable bridge networking. So I skipped that as well.
The good news is that I don't need all the above things. They were just good to have options that I could have used.