I'm not sure to understand question 1 so I'll leave it aside for now.
Question 2 and 3 should be answered thanks to this tutorial, an implementation for question 4 lies in this tutorial and this same tutorial might possibly answer question 1 (it's a video tutorial displaying some workflow).
Question 5, well...
Already complete the 4 first questions/2 tutorials and then we might talk again about 1 on 1 online game.
It's been made more reachable in r116 thanks to the addition of websockets, but you still need to code an external server.
I don't know if facebook allows such games (probably), and be aware it won't be real time, but turn based is possible.
For the bluetooth realtime, I don't think it's possible at all (you would have to check HTML5's bluetooth support I guess).
You might want to read and check some other tutorials linked in this one, they should give you more experience and a better idea of how to use Construct 2.
Also rather than google, prefer a forum search you might get more interesting/precise results.