The V2 Bolt also comes with 2 parts needed. Those two parts (Mag Catch and Buffer) Need to be installed.
I haven't heard about the V1 bolt and new bolt catch. BUT: The new mag catch is STRONGER to accommodate the heavier Buffer. From the photos I've seen of it, it's just a reinforced part so should work.
The Cradle reducer WILL work in the V2 Bolt.
The V2 bolt no longer requires the "retaining" band and INCREASES Felt recoil. Some have shown wear on the bolt at thousands of rounds down range. The KJW still has had no catastrophic failures even with the heavier buffer.