I agree with the Lavos death flashback things. His ineer forms operate much like a TV or a PC. When you pull the power cord, there is still a split second that power is going from the disconnected cord to the PC before it turns off. What if the swirly stuff during the Core battle was the power from the cord? The locations and times could be his memory slowly flashing before him. The reason he lasts longer than a PC is that he has time powers, and is slowing himself down to preserve his life. In example, he is stretching out the PC's split second into probably several hours, in an attempt to gain revenge, then make a new cord to the planet/Entity. So without the cord plugged, Lavos could probably move faster than light, but being slowed down made him go at 'human' speed. As for vengeance, remember that Lavos wanted revenge in Cross, which is why he wants to destroy spacetime. Lavos knows he was dying, and wanted to take Crono and company down with him, or at least kill them with enough time left to make a new umbilical cord to the Entitiy.
Does this make sense?