Dead serious. And keep that console war cancer dead and buried in the 90s and try to behave like a grown adult...
I don't know what kind of "standards" you're comparing this to, but this is by all objective and reasonable standards a high effort remake. At least, up to the point before you start to get into "reboot" territory, like the new Resident Evil or Final Fantasy 7 "remakes". Games that barely still resemble the originals and are pretty much entirely new games.
Mario RPG Remake is not trying to be a reboot, i'm very relieved it isn't, it's just a massively enhanced overhaul of the original with greatly improved graphics and sound, a bunch of small but important quality of life changes and some new post game challenges. There aren't many remakes out there that can claim the same level of effort as this, that's simply a fact. It's reminiscent of the leap from the original NES/SNES versions of Final Fantasy 1, 2 and 4 to the PSP remakes. Except in Mario RPG's case, there weren't any other progressively upgraded versions released in between. Like I said though, the developer of this remake Arte Piazza also made Dragon Quest 4, 5 and 6 on DS. Which are also probably the best comparisons to the effort that went into Mario RPG remake, as they are themselves very high effort remakes of their own games as well.
And please, by all means link to the rom hack for the SNES version that implements the QoL features that were made to this game.
Only two examples come to mind. The Bruce Lee reference was cut (likely because his estate is reportedly difficult to deal with). And the Blackjack minigame in the casino was replaced with a card memorization game. Though the slots are still there. The suggestive "found Peach's ???" easter egg is actually still there. Some enemies have different names. But the English script is still like 95% based on the US SNES version. The secret boss has the same name, but they mixed in some of his original dialog cut from the JP version.
They did not. The content additions are some additional super bosses for the post game (and they are actually challenging and require both skill and strategy), as well as new more powerful weapons. If there's more beyond that, I haven't heard of it.