Dslr'S - Full-Frame Or Not?

I remember there was some photo enthusiasts in here and I thought I’d ask a couple of questions regarding DSLR’s as I’m finally taking the step to get one and semi-retire my old SLR workhorse.
I wrote up a little text over at tumblr, and I’ll just link y’all there, it’s not very long and if any of you lot have any advice concerning my questions it would be greatly appreciated.