The LG 30FZ4D that is in fact older than the LG 30FS4D, by almost a year. I can only presume that the FZ model was phased out in favour of the FS model, as this was the CRT's last stab at sticking around in the face of lower priced LCDs and the high end Plasmas (and at least at the time, DLP as well) looming large over them. Folks just wanted a smaller footprint. (And larger screen area.)
About Trinitrons, the phosphors are indeed striped, the goal of this is to give a finer image, not just vertically, either. Because the aperture grille is made of wires instead of a perforated sheet (a "shadow mask"), the horizontal gaps between each stripe of phosphors is more and more miniscule. Even back in the analogue era this allowed for a finer, more detailed image in general, and a brighter picture as well.
It's funny that you mention the red at the corner of your screen. When I read the reviews for the TXN model that I picked up this weekend, I read A LOT of tell of "great screen, just change the setting to fix the red push first." I think you are probably seeing that here, chances are the previous owner never corrected this. Most people never correct their colour at all, and many of those who try do so badly, even with newer screens. It's worth a try at least as you might get this issue to go away. Service menu settings may be worth looking over as well if it is out of convergence. Many aged tubes have this problem, especially if abused over time.
As always, write down or record every single service menu setting somehow before you change ANY setting at all.