"How do you limit enery for say ls only?"

You dont.

"What is the drawback of farming dyna now? (Before you lost exp for gear/ currency)"

24hour time limit adjusted rate of coin drops.

"Why does the game have to be get exp while you farm for good gear now? ( I do not like this)"

Game growth/evolution?

"Will mobs be changed so exp gain is reasonable for 90/99?"

Im guessing it'll follow a smiliar exp growth to abyssea

"will dyna be updated so people have other reasons to go there besides dyna currency?"

Isnt that the whole point of refreshing the event >.>

"Can new types of synth items drop? ( this goes with the question above)"

Chances are high

"Because of daily entry would there be less drop rates on 100? Maybe only allow boss pop NMs and NMs with a chance of a 100 drop?"

They said they were adjusting coin drop rate to balance out the amount of coins ingame globaly. Did you not read the notes?