Rhodes Tunnel:
Entering will cause all weapons to level down, unless the Road's End boss is defeated. (Boy, am I going to have a hard time on this mod... ^_^")

Entrance. Boss: the blonde girl who's name is being voted about in a poll. Going to the Dragon Room requires beating the girl in combat. Her theme is A Darkened Heart in the boss fight.
Those blocks with the red in the center can only be destroyed by Deleet.
...
Maybe I could add a Life Capsule there after Inoratu is befriended?

I think you should... A Darkened Heart... that's how I feel. That song... it conveys my mood exactly...

Dragon Room. A room with the Twin Dragons of the version. The exit to this room can only be used if the treasure is opened. Their boss theme is Inferno Gaze.

Their gaze can't set the room ablaze...
It's Frost...

Open Path. Boss: Coolio. Two Shadow Clones appear at first (the first gets crushed by a falling block at the top). Then the real Coolio pops up. Defeating him allows leaving the room. Boss theme is HH BG Battle (a song from Wayne's Haunted House Story). Coolio's main theme is Fight (also by Wayne).

Say... will those songs be Frost only?
And Shadow Clones...?

Road's End. Boss: unknown. Defeating the unknown boss allows one to enter Sparkle's House. Current themes unknown. However, major bosses will not be used here.

How about... another Balrog AI? Or an Igor...?

Background music: Once in a Blue Moon (because the background has blue moons)

...

So, what do you guys think?
Is that a good enough "boss rush" tunnel to Kimlasca Town?

I think so... The song sounds great...