In the first one, Liam's daughter was taken.  This time it's him and his wife.  Next time, I guess it'll be his neighbor Ron?

The bad guy looked pretty angry.  I know I've seen him somewhere else.  He looks like he's from somewhere in Eastern Europe or the villain in a Die Hard movie, but that may just be the costumes and lighting.  I can't tell if he's angry because of something Liam did in his past life (as a CIA guy) or in the first movie, but it's probably something from the first movie.  They established everything in the dialogue which I couldn't hear over the dog barking at the guys mowing the lawn next door.

None of the minor bad guys do anything besides shoot and die.  Liam's daughter this time runs around in a bikini and learns how to use hand grenades.  She also gets her dad a gun somehow, but I was too distracted to follow how that actually happened.  Seemed pretty far-fetched to me.

I couldn't hear what he said over the kids screaming, but Liam talked a lot on the phone again, just like in the first movie.  This time it seemed to be mostly to his ex-wife and kid.

It's hardly a spoiler that the bad guy dies at the end.  There's some dialogue beforehand (couldn't hear it) but whatever deal was on the table gets cancelled shortly after Liam kills him by pushing him on something.  It looked like they were in the basement from Saw, if you remember that opening scene.

I speculated to my wife - who was even more distracted during this one - that since there was no one left to be taken, for #3 they're probably going to go after the grandparents or something.  She didn't answer because the kids just dropped a popsicle on the carpet and then the baby sat on it.