Flashforward and time travel theories - Theory 1: a different future

The last episode I saw of Flashforward (n° 7, "the gift") caused some discussion and thinking about the possibles "time shifts" scenario in the series.
This serie of post contains SPOILERS on the Flashforward series and on episode 7 in particular. So, if you haven't watched any episode, please start by the pilot. If you've not seen "the gift" yet, stop here and come back after ;).

There are different theories on time travel and related paradoxes. I will try to apply some of them to the "flash forward universe" and see which one match it best.
I'm starting from 2 basic assumptions:

1. The flashforward shows something "true", something that would happen in a precise "possible word". The flashforward is not just a dream, created ad-hoc with no reference to a possible future.
2. A specific "possible world" setting, without any external intervention (par example people causing flash forwards), the future is fixed: starting from the same exact variables events will always evolve in the same way. 

Theory 1: a different future

Let's start with the simplest theory. In figure 1, there is the "normal" timeline. This is the timeline of events in case no flashforward occours. All the timeline is drawn in a full line, assuming that the future is pre-determined by the starting situation.

Figure 1: normal time flow (no flashforward involved)

Obviously, one flashforward must occour, on October 6. On this date everyone has a flashforward of april 29th.
What happens to our timeline (Figure 2)? The first timeline becomes a possible world, where no flashforward was involved. Our world is rapresented in the second timeline. We have now the flash flashforward on October 6. What is shown in this flashforward? In this hypothesis, people see what would have happened on the world WITHOUT the flashforward. In their 2 minutes and 17 seconds they see what would have happened on april 29th in timeline 1.

Figure 2: Flashforward coming from "natural" time flow

This is therefore a future that can be changed: a new variable is introduced in the world, people have seen their future and can act in different ways in order to change it. What will happen in the "real" world on april 29th is no more pre-determined (dotted line) but can change according to people choices.

Good points:

This vision is quite simple and easy to understand, there are no (let say less) temporal paradoxes. Time "restarts" from the flashforward and the world history is rebuilt according to people actions. Anything can happen, both "now" and on april 29th.

Problems:

It is rellly hard to fit this vision with the flashforwards seen until now: why is mark investigating on the flash forward? How did Olivia meet Lloyd, if in the first timeline the accident that caused Dylan hospitalization would not have happened? How do all other clues rely? How could "blue hand" groups exist?

Addressing the problems:

It is a bit hard to believe, but all the Mosaic investigation in the first timeline, might be based on something else, might not be involving the blackout. In that possible world, Mark might be investigating on a different case, or maybe on the group of people that will cause the blackout in timeline 2. Olivia might meet Lloyd any other possible way, and any other coincidence might be explained. Blue hand might be something different in this world, maybe (still?) connected with people behind the flash forward.

Further Theories are presented in the following posts:

• theory 2: pre-determined future
• theory 3: external interventions
• theory 4: nested flashforward

References:

THE PHILOSOPHY OF TIME TRAVEL By Roberta Sparrow (PDF)
Flash Forward Wiki Wikia (Spoiler Alert: this wiki is up to date with the last episode broadcasted in USA)

Acknowledgments:

Thanks to Came, Bond and jjescalante for discussions ;)

Comments Welcome!