1) No data as I don't work there. Hopefully someone else can weigh in on this.
2) It depends, what department are you looking at, Ops, Engineering, Training, etc.? However, since it sounds like you've applied and received an offer, there must be something missing at your current job. As far as hours, I believe most areas average 40 hours per week (Ops might be more), although operators work shift work with 8-12 hour days (depends on the plant). There is some amount of stress, especially if you're going for an SRO license, but it's manageable. If you end up working on scheduled days off, you will probably get overtime of some sort for it (hourly workers typically get time and a half, salary get straight time).
3) Depending on your contract, you may have to live with in the ERO response time (typically 1 or 2 hours), so you can live fairly close to Augusta or you can live right by the site, it's really up to you. Again, I don't know the area, so I can't be more specific.
4) I'd say it's a good career choice, but that's my opinion.