Do -breaker skills affect Brave weapons?

Yes they do affect Brave Weapons

They don't. Reinhardt is always guarantueed two hits upon initiation, unless he dies from something like Vantage.

No, the second hit he does is still his first attack. So he would still moonbow (+quickened pulse) you if he gets to attack first.

Yes these breaker skills do affect Brave Weapons.

Hmmm, in Arena, never meet Reinhardt which was able to kill my +hp Sonya anyhow (maybe just my luck)... like she always kills him (with that res she is perfect bait for him, honestly), unless she has already taken dmg.