It is the NTC that decides its policies. Therefore they own all these cards. Others can try to persuade it to change its mind, but it is the NTC that actually can turn the cards.
A major difficulty that the NTC has is that it has is that the people of Tripoli do not trust that it will do as it promises. The people of Tripoli are afraid that the NTC's army will commit war crimes as they sweeps through Tripolitania, and that when they reach Tripoli there will be a bloodbath. They are afraid that they will centralize power in Benghazi (despite promises not to). This lack of trust is a problem both for Tripoli (they think the cards will actually be played) and for the NTC (they have to convince the people of Tripoli they mean what they say).
The people of Tripoli would like the NTC to hand over power before elections, but the NTC wants to retain it.
Finally Gaddafi (or at least his sons, or his supporters, or at the very least the people of Fezzan) would like to have a role in the future government. This is rejected by everyone else.