You need a second boar to have piggies, doesn't have to have any stars. There's a 50% chance it will be a two star. Then you can kill off the no-stars.

The thing where they stand in the corner is a known bug. I'd kill that one off once you get a few replacements.

Added: wait ok you did get them started. That's a lot of questions to keep up with. Food is only for breeding, so it doesn't matter that much. They seem to all grow at the same rate. Piggies only seem to take a few minutes if you have enough space. Don't know the exact numbers.

When you get to the mountains you will want to completely enclose your pig farm, especially if you go in the caves.