Star Wars plot details?

A rumoured basic plot outline for episode VII has been doing the rounds online.
Do not read on if you’re planning to see episode VII completely fresh.

John Boyega and Daisy Ridley play two friends who find a severed hand holding a lightsabre.
They recognise the object as an old relic of the Jedi and set off to return it to the proper people. On the way, they meet Han and Chewie who recognise that the lightsabre belongs to Luke, whom they haven’t seen for thirty years.
The foursome then set off looking for the fallen Jedi master.
Meanwhile, a weapon capable of destroying an entire solar system is being developed on an ice planet.

I would certainly say that that plot sounds very plausible, it completely blows out the speculation that Ridley is a young Solo.