Thanks, Phil
1. Network railcard
2. Three times a week, probably
3. Gaining in 7am, coming back 6pm
And I'm assuming travelling 47 weeks of the year, allowing for holidays etc
There are others on here that can possibly come up with better alternatives, but a very basic lookup suggests an annual season is probably the best option as you have already intimated. The Network Card will not be valid at the time you propose travelling (unless you will be travelling at weekends or Bank Holidays.