Number of seasons is irrelevant. How many days a season do you ride? If it's one, you can probably get away with the same equipment for the rest of this century.
What you describe for the board is normal wear and tear. This is like measuring a car's quality by how often you have to change the oil... It is by no means a yardstick for durability.
The binding cable fraying and the back of your boot splitting may be linked. Try re-aligning and re-adjusting the setup on that foot from the ground up. You might be pushing the high-back into the back of the boot way too hard or something.
It's too late to salvage to boot with anything short of marine grade epoxy, and even that might not work.
EDIT: I tried keeping the first new board I ever bought scratch free.... that lasted about five minutes into the first run before I gave up. You get a board to beat it like a rented mule, not rub it with a silk tampon.
Yeah, I got over the wear and tear on board soon enough...realized I was just obsessing over cosmetics. It's still a sick ride. But the split boot/frayed cable could be linked, as you say. Seems coincidental that both probs happened on my back foot. I Gorilla Glued the seem last week and got a full day of riding out of it, but it split again, natch.
BTW, in answer to your first question, I ride about 30 days a season; this season, ten of 'em were at Tahoe. I didn't think that was too excessive. What's considered "a lot?"