Where are you seeing +1s or +2s? I don’t recall any weapon in the game off the top of my head that provides +2s.
No. It means that if you have chosen to Attack, and your opponent has also chosen to Attack, you treat it as a versus test rather than an independent test (which attack against attack usually is). In other words, choosing Attack is a fairly safe option when you have a bow. This benefit is negated if your opponent is also wielding a bow or a crossbow.
You’ll have to wait for the end of the conflict to pick it up (assuming it isn’t lost or broken as part of the compromise of the conflict).
For example, the party decides they want to kill a group of Kobolds. After the first actions, they are almost all dead! So now they want to Flee! Can they switch to Flee! with their remaining disposition or must they now complete the Kill conflict for good or ill?
I like the optional rules - but one question - if someone gets knocked to 0 disposition in the fight, can’t they have “fled” anyway? I ask because I thought it was a role played decision with the fate of a character going to 0 - that character can be unconscious, stunned, flee, etc?