You got the right answer, Rantz Rantz Revolution, but your reasoning is a bit off.
"A last addition to a work of art" does refer to Finishing Touch.
"Steep going here, beware of falling rocks" refers to Climhazzard, and requires a bit of meta-knowledge. You see, the name is actually a mistranslation - the attack was supposed to be called Climb Hazard, in reference to Cloud jumping high while executing the attack. Steep going and falling rocks are common hazards in mountain climbing.
"Screw your courage to the sticking place" is indeed Braver - being brave takes courage.
"The nighttime spectacle in the sky" refers to Meteorain - the line is referring to a meteor shower.
"Traverse the scars of yesterday" is Cross-slash. Traverse = cross, scar = slash.
"Shine a light from the sacred sword" does refer to Blade Beam. Light = beam, sword = blade.
The last two lines refer to Omnislash, and its original Japanese name, which translates to something like "Super Ultimate War God Conquering Slash", hence the reference to the gods giving you power.

Nice job, well done! I never thought that one would last that long.