Nice description, but a couple of things are inaccurate. First of all, the first funnel actually fell to port because of the 9 degree and increasing port list. This matches Officer Lightoller's testimony (who was on the port overturned collapsible) of the forward funnel collapsing "inches" away from him. This is an exaggeration, of course, but this indicates a port collapse for the first funnel.
Also, it is physically impossible for the bow to bob back up from the water with a nearly three-hour steady flooding. At the time of the breakup, the bow was almost completely flooded, making it a dead weight that drops like a stone at the point of separation. I think what the survivors who claim that this happened saw was the forward grand staircase lifting from its foundations and being shredded apart when it shot out of the dome. Once the dome imploded, a cylindrical column of water would invade the area (much more catastrophic than what the film depicts) and because of the buoyancy of the oak in the staircase, it floated against the water and lifted up. This actually is what happened on the set of the 1997 movie set. The stairs were built almost exactly as the real ones were and they lifted up as they shot the dome implosion scene.
Take a look at what happened:
(Skip to 2:00)
This would also help explain why there were reports of large amounts of wood floating on the surface the next day.
Here is what I believe happened from the point of the bridge beginning to drop underneath the waves:
The band finishes playing their last song, "Propior Deo," and the ship takes a sudden dive. This is the bow accelerating downwards. The port list increases by a few degrees. Four explosions are reported as this point. In my opinion, this could either be the beginnings of the breakup or exploding boilers. The base of the first funnel becomes submerged by about 20 feet and the funnel caves in due to the differential pressure between the water and trapped air, sending it down to port. As the bow continues to drop, the skylight over the dome of the grand staircase implodes, and the stairs are forced up and out of the ship, giving some the impression that the bow rose back out of the water. Coal dust ignites in the bowels of the ship and shoots an explosion in the form of a ball of fire out of the second funnel. This funnel kicks to starboard toward survivor Jack Thayer and smashes in the gymnasium. The stern begins to lift out of the water, exposing the rudder and propellers. At this point, Titanic is now rotating at her new center of buoyancy upwards. At 23 degrees, the ship breaks apart somewhere between just before or under the third funnel. The break begins slowly and the stern gradually settles back until it's halfway down to being back on a level keel. At around 15 degrees left until the way down, the stern drops "like a cork" and remains there for about 20 seconds. The main electrical power supply is cut as a result of severed pipes and cables, but the emergency lights remain on, allowing the stern to be sparingly dotted with light. The bow swings down, but half of the keel is still attached to both halves, slowly dragging the stern upwards and to port, allowing it to perform a 180. At an angle of about 60 degrees (as described by Lightoller) the emergency lights go out. Because of the mass of trapped air left in the stern, it explodes out of the windows and decks of the superstructure. The refrigeration units explode and people as blown off the sides of the ship. This is all a part of the roaring noise described by survivors. The ship detaches in complete halves and the stern drops down into the water at 2:20AM.