This is a really good post, thanks for writing. I just finished my first playthrough of the remake this weekend, and as someone who has also played the original many times over the years (most recently last year) and considers it possibly my favorite game, your thoughts echo mine very well across both pros and cons. The combination of unreliable staggers + more sluggish movement in particular took me FOREVER to get used to, I was at least halfway through the game before I felt somewhat comfortable in normal encounters. Playing my first playthrough on hardcore probably didn't help either, but I believed the difficulty selection screen's advice lol (which suggested hardcore if you played the OG). By the end I had found a better rhythm, which relied on staying in motion when in doubt as to avoid the slow wind-up run time in case I needed to move. I also started relying more on grenades as CC later on, as you mentioned they are now better for that than shotguns (though I still stuck to the striker out of stubbornness for what I want the shotgun's role to be!). The knife changes are also a mindfuck, as I had to retrain my brain away from the OG's combat loop to never waste durability on slashing enemies, and that took a while. The remake on the whole rides a weird line where it is both close enough to the OG to be recognizable and I want to play it similarly, but also just different enough that that doesn't really work. I think I may have preferred it to be a cleaner break in some ways, more of its own game so that the line wasn't so blurry.
Anyway, I did end up enjoying the remake overall by the end, though I can say with full confidence that I reject the idea that it's a strict upgrade or replacement to the OG. I can see how some would prefer it, but it's a different enough game that I think it as best presents as an alternative, with neither version being the universally agreed upon definitive one. Then for someone like me (or you), the OG will always win out, not only because of nostalgia and how impossibly impactful it was (which is huge!), but also because I legitimately do still prefer it's mechanics, movement, and combat loop.
@justin258: I also struggled with the movement in RE4 remake, having just finished Dead Space remake before it as well (which I think controls very well). Out of curiosity I booted up both the OG RE4 and the RE2 remake after I finished RE4 remake to directly compare how they feel. Not that I did a super scientific study here, but OG RE4 felt like easily the snappiest movement of the 3 to me; both the ramp up to running and the quick turn are lightning fast (not to mention swapping weapons is instantaneous). To my surprise though, RE2 remake didn't feel that much faster than RE4 remake; not as much as I was expecting given my memories of it. I do think the ramp to run is a little faster than in RE4 remake, but my current theory is that the movement in RE2 remake never bothered me simply because it never demands you be faster than you are. The zombies in that game move much slower than the ganados in RE4 remake, you never fight huge hordes in RE2 remake, and you are generally in confined environments like hallways to boot. Put another way, it's a different game that supports different movement, and I felt that RE2's movement worked well for the game it was. RE4 remake's movement feels extra slow compared to how fast your enemies move, how big the rooms are, and what you are asked to do, which likely makes it feel even slower than it actually is (though I also do think it is a little slower than RE2 remake). I think that dissonance is a large part of my frustration with the movement, and that things like the knife counter feel like subpar quick fixes to smooth over just how slow the player is compared to the enemies.