Thanks for the post.
At first it did confuse me, I watched a video on one of the links you posted which helped clear things up to what I understand which is this:
A rom is basically an image of a tablet that someone has created. By flashing a ROM that someone else made takes out the hard work. Like a theme but much more in depth in the way that the back end and system is modified as well.
So is a ROM just like kinda what I've done with my extreme, meaning I have kept the standard ICS build (which most people want it seems), but I've removed the bloat, contacts, phone, browser, ebuyer thing etc. I've then added Apex Launcher, Simple Text, Beautiful Widgets resulting with something like this (I've not finished as of yet). Something like this
http://db.tt/QALjmdV5, (this is a screenshot of my One X).
Is making a backup of this once I've done it not more or less a ROM?
EDIT: Silly work PC crashed mid post!