^Rings respawn on many levels, particularly the ones that are lap races in disguise (sometimes, they respawn in different places per lap, such as in Rooftop Run 2). It might be better to ax the entire division. Although I will say that in cases of rings respawning in the exact same location, we've already had that issue in Sonic 1. We've worked around it, and kept charts.
Scores on Night levels, what with infinite combos, I don't know much about. But from what I can see, your score goes up WAY faster via critical attacks than it does via combos. My combo bonuses, even for 50 hit combos or so, have been in the hundreds of points, whereas the smallest critical attack I've seen awards 6000 points.
Where you say we should add missions to be consistent with the rest of the charts, notice that Riders and Riders 2 never had missions tracked, but Secret Rings and Rush Adventure did. SkyLights made an argument for axing missions in Rush Adventure, too. What consistency?
Also, since when did we ever track scores or rings in bosses anyway (3D Blast aside, since it doesn't have a separate division)? It's only time tracking. I'll check the final bosses again, though, and I did indeed forget to add Tornado Defense to scores. Added now.
EDIT: Dark Gaia does get ranked.