Finally; was worried you fell asleep lol.
In order...
Yes, it is important to the discussion unless your enjoyment in watching blitz is derived by seeing two people push wooden pieces and punch clocks. How much someone can follow blitz as it's being played is not only relevant to the discussion, it's essential!
No, that's not enough complexity when most games last from 35 to 60 moves. Even players in tournaments with classical time controls will "blitz out" the first 5-10 moves depending on how well they know the opening. The real complexity comes in the middle game, late middle game and most endgames. That's precisely when having more time leads to better moves and a better chess game with fewer errors.
I'm not arguing that bullet or blitz chess games are less complex - if you froze a bullet or blitz game and did the same with a classical game they might look the same - to a point and if the observing person isn't a GM. What I am saying is that bullet/blitz players are Less Likely to find the best moves in complex positions, which leads to a lower quality chess game.
How much of a blitz game are you really able to follow?
I think where we disagree is on this statement: Blitz and bullet chess lead to lower quality chess games. I think they do; you apparently disagree.
To each his own. Play/watch blitz to your heart's content and I'll play chess with classical time controls or correspondence chess to my heart's content.
But IF you believe blitz doesn't lead to weaker chess due to players not having enough time to find the best moves, try this experiment: Take two GMs of equal or near equal rating and have one play with a time control of 5 minutes for the game, and the other play with a time control of 40 moves in two hours and an additional hour to finish the game. See who wins