In the first episode, there's a mutated dog creature thing. No whimpers, although later in on the season, there is another dog that gets fused with another character, and you can hear whimpers, but that only lasts for a short bit. The dog in there ends up being fine.
There are a few cases of it, but the most notable one happens in the 19 minute mark of s1:e5 where it is actually pretty graphic. Its reversed in a few short seconds, but it's pretty gory before it does.
Sort of. The main character gets what he wanted throughout the whole season, but it came with a sacrifice he's trying to reverse so he could have his cake and eat it too.
I think it's implied at the end of the season that the main character's family dies, and it sets up the future season about how he's going to bring them back through time travel.
In episode 2, during a montage one of the kids in a robot suit blasts a cat. It's pretty bloody, so if you're sensitive to that kind of thing, definitely skip past the 18:56 mark.