Can we buy tickets for the Kung Fu performance when we arrive at the temple?

And if so, would we risk they sell out in advance?

Should we stay overnight if we also want to visit the Taoist Temple and astronomical observatory in Denfeng?

How far is the temple and observatory from Denfeng?
Could this be a day trip from Zhengzhou?

If we also want to see the Grottoes, is it better to go there directly from Denfeng or go back to Zhengzhou and make a day trip from there to the Grottoes another day? We will be in Zhengzhou for 2 weeks. Thanks.