1) yes, I'm already using Whatsapp Business
2) I developed a program for to send Whatsapp message in automatic mode, received from a PC.
The program is use in a library that sell books online, about 100 books every day, so about 3000 chat every month.
When the smartphone have many chat it don't works very well, so a human need to select each chat and delete it, but it need many time.
3) Yes, I already takes a look at business API, but it ask to me to contact a "partner", ok I will try it
4)
The Businessaccount provide a Api which you can use using okhttputils2.
Can you tell me more about this ??
Best regards
Sergio