Finding a balance between the two could be tricky, too much or less of one or the other might alienate both, but Disciplines are one that should maybe have a starting limit, either based on dots or age of character or a mixture of both. For example Thaumaturgy has some pretty powerful abilities that you might not want everybody to have at the start, so having a limit on what level a character can take their discipline to at the beginning could be something to consider, take for example Tremere who follow the Path of Blood, their highest level power can be Blood Boil which, as the name implies boils their victims blood until they explode, that's probably not something we'd want people to have access to right from the start, which would mean either limiting the rank you can get too, or maybe for example limiting it to only certain points in the story when it can be used, in which case the GM can PM the Tremere character/s and say what's going to happen and when the ability could be used, at least in the overall story.
Like Andy said in reply to something I said about Dominate, if there's a scene between two people that's outside the main narrative, it can be decided between those two or if the writer is writing a scene between their own character and an NPC of their creation it can be given free reign of use in those situations.
Another thing to consider could be merging similar Disciplines, for example the highest level Path of Blood options for Tremere are Cauldron of Blood or Blood Boil, both are pretty much the same ability expect Cauldron burns victims from the inside and Blood Boil burns the blood till they explode, which in theory could just be turned into Blood Boil but the Tremere can choose whether to explode them or just burn them...maybe tie it into their Discipline level in Thaumaturgy so that only when maxed can they explode anything lower and it just burns them to different degrees depending on their point number.
Same with the other Disciplines for other classes, I was just using that as an example as I know Thaumaturgy better than the others, another example would be Malkavian insight, they may be bat shit crazy but those voices can sometimes be right....or completely wrong, in which case the GM could PM a Malk player and tell them what's going to happen in an upcoming story event, which could either be true or false that the player can write about and regardless of whether it's true or not it fits perfect for a Malkavian. And if over the course of the story what the GM tells the player is true some of the time, then the rest of players will have to decide to trust the Malk's Insight incase they are right, or not believe them because they're crazy and it could be wrong.