Sagano Scenic Railway Tickets

I planned to visit Kyoto sometime in April 2013 for 4 days.

1. Can I purchase the Sagano Railway Tickets at Kyoto Station when I arrived Kyoto on the first day even though my plan to visit Arashiyama and Sagano area is on the 3rd day ?

2. Does Sagano Railway Tickets include the journey from Kyoto station to Saga Arashiyama station ? or

3. Sagano Railway Ticket only covers from Saga Arashiyama station to Kameoka station ?

Thanks in advance for your help :-)

Can I purchase the Sagano Railway Tickets at Kyoto Station when I arrived Kyoto on the first day even though my plan to visit Arashiyama and Sagano area is on the 3rd day ?

Yes, the tickets can be bought at the JR West ticket counters (not JR Central ticket counters) at Kyoto Station up to a month in advance of travel date.

Does Sagano Railway Tickets include the journey from Kyoto station to Saga Arashiyama station ?

No.
3. Sagano Railway Ticket only covers from Saga Arashiyama station to Kameoka station ?

Yes. Or to be more accurate: it covers only travel on a selected section between Torokko Saga Station and Torokko Kameoka Station:
http://www.japan-guide.com/e/e3965.html

You don't mention what date you plan on taking it but obviously try and avoid the weekends as they are more likely to be booked out then.

Enjoy your trip!

Yes. I planned to travel on a weekday, 09 Apr'13 (Tue).

Also, can I just purchase a one way ticket in Kyoto Station for travel from Kyoto to Saga-Arashiyama on the JR Sagano Line if I don't have the JR Passes brought in advance to exchange ?

Thanks.

Also, can I just purchase a one way ticket in Kyoto Station for travel from Kyoto to Saga-Arashiyama on the JR Sagano Line if I don't have the JR Passes brought in advance to exchange ?

Yes, of course.