What do you think will happen to the price after all the bitcoins have been mined?
Sorry I dont have a time machine...yet.
What do you think will happen to the price once all the bitcoins are mined, and how do you think bitcoin will affect the global economy?
Again, I dont have a time machine....yet.

Does it really matter that much to anybody of this age?
Like we are 119years from that event and I am sure the number of forum users of this time who will survive to see that day is close to zero, comparing to what the global life expectancy is:
https://ourworldindata.org/life-expectancyBut to answer you real question which is whether bitcoin will have any impact on the economy at that time - as long as someone keeps using bitcoin, its demand will remain. Miners will continue mining the transactions and they will not stop doing that.