Gaikai is the only way it will be "bc" They stated before that it would be impossible to be able to play a ps3 game because of how different the two systems are. Also apparently they lost a lot of money on the bc version of the ps3 so I doubt they would every make a true bc ps4
No, because they didn't have backwards compatibility in mind when developing the Wobble. They are going to use Gaikai because it'll be a separate service they can update later and bring in more support. Look what happened with Xbox 360 and PS3, not everything was capable, so Gaikai will at least bring more working titles. But let's not forget, they can sell the games back to you via a service, selling you what should already come with the system!