Also, then, what are the optimal 12 rolls and songs for DD in burn?
No bloody clue, depends on which other buffs you're getting, if your BRD is using soul voice etc.
For instance if you have Dia4 and bolster Idris Frailty on the target and the bard is using Soul Voice, you probably won't need more then Honor March, Minuet 5 and Minuet 4 to cap attack. Probably less than that when you factor potential food, Smite traits, Berserk and such.
Likewise with Chaos Roll.
Was just making an example but the same applies with Haste for instance. Will you be getting entrusted Indi Haste? Diffusioned Mighty Guard? Haste 2? Etc.
I really don't know how to help you, it's way too situational. For instance on some targets you want to use defensive songs (carols) to reduce the chances of bad debuffs sticking on your DDs. Albumen is a pretty fine example of this scenario.
I would say Honor March and Samurai Roll are probably mandatory, the rest is very situational. Personally I would use COR for the "unique" buffs that only COR can give, instead of "wasting" a roll slot for stuff you can get from other buff slots like songs or GEO bubbles (attack or accuracy, for instance)