By having AEM Site and AEM Form were installed in different servers, how does it work if I develop a jar package for AEM Site? Shall I deploy it on AEM Form as well?
If you have different servers and that jar provides some utility to both sites and forms then deploy on both. If its specific to site then you can keep it on the respective server only.
In my architecture I have 1 Author and 2 Publisher, when I publish a template how it works? will the template be published in both Publisher? What is your suggestion?
Yes, the asset will be pushed to all the agents configured on the author. You can publish forms and all its fragments, themes associated with It will also be pushed.
@1982luca