Aomori to Towadako back to Aomori

Hello, I plan to go to Towadako from Aomori and back to Aomori on Oct 18/19. Stay 1 night in Towadako.
18Oct: Aomori - Hakkoda Ropeway (stay about 2 hours) - Sukayu Onsen (stay about 1-2 hours) - Towadako.
19Oct: Towadako - Lake Cruise (Yasumiya-Nenokuchi) - Oirase stream - back to Aomori by bus from Ishigedo.

1). Do we need to book Bus from Hakkoda and from Sukayu or just get on the bus when it comes. We plan to have Japan Railpass.
2). Any other suggestion on itinerary? Is it better the other way around?
3). Any suggestion for hotel at Towadako?

" Do we need to book Bus from Hakkoda and from Sukayu or just get on the bus when it comes. We plan to have Japan Railpass."

No, no booking for this bus, it is free for JR pass holder.

We reserved our Hachinohe-Towadako and Towadako-Aomori bus seats in advance but on both occasions there were less than 10 people on board. But we travelled off season during the winter month of Feb and situation during Oct could differ greatly. If it is late Oct a reservation is definitely necessary as it is autumn foliage season in the area and Oirase Stream is a very popular koyo destination.

Note that you can ride the bus without addition fee only if you are using the national JR rail pass. JR East rail pass is not valid on that particular bus line.

For onsen hotel in Towada-ko, we stayed at the following one and found the service to be excellent with great food.
http://web.travel.rakuten.co.jp/portal/my/info_page_e.Eng?f_no=9688

It was out of our budget but a friend who had stayed there recommends the following.
http://web.travel.rakuten.co.jp/portal/my/info_page_e.Eng?f_no=14840