Bleed + Ballista + Rapid

Hi. I want to try bleed archer. Looks like Siege Ballista deals heaviest physical strikes of all bow attacks. My questions:
1. Ballista has "duration" keyword (like any totem). If I'll take bleed chance passive, will Rapid Decay boost bleed damage triggered by Ballista?
2. Is Bleed viable as main damage source?

1. Yes, it will also reduce ballista duration, obviously enough, but won't affect bleed duration (unless they messed with it since prophecy but it lasts a fairly long time by default so that's of little consequence).

2. Depends on the build. It can do good damage on certain setups and nothing is outright immune to it, however bosses and enemies that don't like to move (Shaper or Atziri) will be hard to kill by inflicting the status and waiting for them to drop dead.

It works really well combined with knockback (eg: from the bow knockback on crit node), since being knocked back counts as moving, and also most enemies try to move forward again after being knocked back.