Tsuruoka to Haguro san to climb bus system

Dear all, please kindly tell me the following:
1. I plan to take shonan bus from Tsuruoka station to Haguro base about 2PM then climb the Haguro san.

When I reach top of Haguro san, can I use the shonan bus to continue from Haguro san to Yudono san then back to Tsuruoka station?

2. Is the bus system very complicated and strict?

3. Must I book the bus or I can just go to bus area and take the shonan bus anytime come?

4. Does Tsuruoka Station have lockers to keep my big bags while I go to Haguro san?

Any other advise is very welcomed, thank you.

Thank you Very much, Tony

When I reach top of Haguro san, can I use the shonan bus to continue from Haguro san to Yudono san then back to Tsuruoka station?

No. There is no direct bus between Hagurosan and Yudonosan. The transportation situation is explained here. You basically would have to travel via Tsuruoka:
http://www.japan-guide.com/e/e7901.html

Is the bus system very complicated and strict?

No, I would not call it very complicated. But it is not easy to use, especially for people without Japanese language skills. Also, the services are not very frequent. Note also the winter closures.

Must I book the bus or I can just go to bus area and take the shonan bus anytime come?

Advance bookings are not possible. They are normal local buses that you just board when they come.

Does Tsuruoka Station have lockers to keep my big bags while I go to Haguro san?

Yes, there are coin lockers, but I am not sure how many and what size.