Yamagata: Zao and Yamadera in the Summer

I'll be staying at Zao Onsen Friday night until Sunday Morning. I was wondering what the best things to do are. I definitely want to go to the outdoor bath at Zao. I was also thinking about checking out the crater and Yamadera. Is that all doable in this time period?

Is there anything I'm missing that would be worth checking out?

I'll be taking the Yamagata Shinkansen from Tokyo, but would it be better to rent a car from Yamagata Station or to use public transit?

Also, any recommendations on where to eat lunch and dinner?

Seeing the crater and Yamadera on the same day is possible.

From Zao Onsen you can take a ropeway to Mount Zao and walk for 45 minutes to the crater. Even if you start at noon you can still make Yamadera since it closes at 5 pm and the trip there only takes an hour from Zao station (I made Yamadera from Tokyo after doing sightseeing there till noon). I dont know about the busses to and from Zao Onsen though so I dont know if a car is more practical either.

Thanks for the input. I'm here now, relying on public transit. It seems it will be sufficient. I'll post here if I run into any issues, for the benefit of future travelers.

While it is entirely possible to stay here and use public transit, I would highly recommend people to rent a car. It will be a bit more expensive than your transit costs, but it is worth the time it will save you and the convenience. You won't have to live by the bus or train schedules and can just go wherever you want.