What to do if I am not a big fan of the charts library

I just discovered JetAdmin and I am impressed. I will start using it. But there is one problem: I don’t like some of the libraries that are being used. E.g. charts.

1/ Is there a better workaround than embedding charts from different environments/websites/tools?
2/ how could I insert then real time chart such as this one - link? I am asking since I want to showcase my own real time financial data. This is crucial for me.
3/ are there any limits to number of free users? Users that don’t sign up and simply just look at the site.

Thank you very much in advance for your help & guidance!