Tell Me About Jobs in 3D Animating

Hey, with me about to start my A-Levels i was thinking of maybe seeing what jobs there are available to 3D animate for video games, i really like video games so i figured i should maybe try doing something in 3D animation and pursue it, i've seen how it all works etc and i think that if i was to properly learn it and get into it i could hopefully get good at it and maybe get a video game job in animation. It would be awesome but unfortunately i do not know how it all works and what i would be required to do. My questions are.

1. In 3D Animating jobs is it purely just 3D animating or is there other jobs expected like being able to design characters etc?

2. What would be a recommended subject to take before going to university that will allow me to do a university course in it?

3. What sort of 3D animating jobs are available?

4. Is a job in 3D animating competative to find and to actually do?

Thanks alot and if you could just tell me some general stuff about 3D animating etc that would be awesome since i would like to get right into it.