Possible Clues:

• Resembling a switchback throughout
• See, the saw goes like this
• Changeable
• Fluctuating, or two words needed to understand the starred clues' "After" parts
• Directions taken by mountaineers in varying spirits?
• Undulating, throughout or vertically
• It's changeable being on the seesaw!
• Variable, like the stock market
• On a high as well as being depressed is like being on a see-saw
• Fluctuating throughout