1) I think the FR/LG soudtrack is generally better than the original, the are definitely some tracks that overshoot "rich" and land firmly in "busy" territory. Viridian Forest, however, isn't one3 of them. It's mostly the battle themes, especially the Champion battle theme that hafve too much going on. Which is desappointing since, battle themes are arguably the most important song in the game and definitely the ones you'll hear the most.
2) You say that as if there aren't EV/IV equivalent mechanics (which are much worse) in RBY. Regardless, lacking things like Natures and EVs is definitely a negative. Why would you want to lose the characteristics that make each Pokémon unique?
Actually, the whole IV did slip my mind, so I am going to give you that one. But I still prefer the music in the original games.
And it is just other things that bother me. For example, the fossil Pokemon are now at level 5 instead of Level 30, making them useless (Hitmonchan/lee comes at a lower level too, but Lapras comes at a decent level now which is pretty cool). Another example is Giovanni's Rhydon being replaced by Rhyhorn, and Sabrina going from being one of the harder fights to being the AI stupidly spamming Future Sight.
Plus, Lance's Hyper Beam strategy is no longer intimidating.