Osaka - What pass to buy for 16 days?

Osaka - What pass to buy for 16 days?

1) What's the different between Kansai Wide Area JR Pass and Kansai Area JR Pass?
2) Can i buy separate JR pass to save money?
3) Is there any JR train from Kansai Airport to Osaka Station?
4) JR pass cannot be use for Metro Station? What pass to buy?

Iternary:
Day 1: Osaka Kansai Airport - Osaka station
Day 2: Osaka - Kyoto
Day 3/4/5: Kyoto
Day 6: Kyoto - Kinosaki
Day 7: Kinosaki
Day 8: Kinosaki - Tottori
Day 9: Tottori
Day 10: Tottori- Okayama
Day 11: Okayamag
Day 12: Okayama - Kobe
Day 13/14: Kobe
Day 15: Kobe - Osaka
Day 16: Osaka - Osaka Kansai Airport