Hi fcnsc ,
Unfortunately, Buttonizer isn't currently supported on AMP pages. 😥
AMP pages uses a very limited version of JavaScript, which makes Buttonizer not function at all.
Buttonizer use Javascript for everything such as functions and showing the button itself.
Regarding the second question, sorry but I don't quite understand it.
Could you perhaps elaborate on the question?
Would you like to know how many Call buttons you can add in a page?
Please let me know! 😄