JR East Pass (Tohoku Area)

From Morioka to Geibikei. according to Hyperdia programme, I will have to take JR Ou Line, Shinkansen Hayabusa10, Shinkansen Hayabusa108 and JR Ofunato Line. May I ask you my friends a favor with this question:
1. With JR East Pass (Tohoku Area) in my hand, which train fee above is included in my Pass and which train fee is not included in my Pass?
2. For train fee that is not included in my Pass, how much do I have to pay?
3. If I want to buy a train ticket for no.2 above in advance, can I do it online?
Thank you very much.

From Morioka to Geibikei. according to Hyperdia programme, I will have to take JR Ou Line, Shinkansen Hayabusa10, Shinkansen Hayabusa108 and JR Ofunato Line.

Something is wrong with your statement. The regular way for traveling from Hayabusa to Geibikei is to simply take a shinkansen along the Tohoku Shinkansen from Morioka to Ichinoseki and then transfer to the Ofunato Line.

1. With JR East Pass (Tohoku Area) in my hand, which train fee above is included in my Pass and which train fee is not included in my Pass?

Everything is included.

3. If I want to buy a train ticket for no.2 above in advance, can I do it online?

I don't know what you mean with no.2. Online tickets for the Tohoku Shinkansen can be purchased here:
https://www.eki-net.com/pc/jreast-shinkansen-reservation/English/wb/co...

If you have a rail pass, you can make seat reservations through the above-linked website.

I suspect that OP meant Aomori, not Morioka.

http://www.hyperdia.com/cgi/en/search.html?dep_node=AOMORI&arv_node=GE...

P.S. : Uji's answer also applies from Aomori.

Dear Uji and the other guest,
You are right. I had made a wrong statement. The true starting city is Aomori, not Morioka. Your answers, however, are helpful to me. Thank you very much.
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