I have went through the Alfresco All-In-One sdk steps and I am able to generate the share.war but not able to generate alfresco.war. It shows only the folder structure as shown in above site.
"Repo" means "repository" and Alfresco is a repository. The WAR that gets created by default matches the directory that project is sitting in, which is called "repo" which is why the WAR is called "repo.war". So "repo.war" can be deployed to your Tomcat server and renamed to "alfresco.war" as they are the same.
You can add your own unit tests to your Alfresco SDK project if you'd like. But there are no standard unit tests that ship with the SDK.
Opinions differ about this, but I would not deploy the WAR files produced by the All-in-One project. Instead, move your AMPs to the server, then use the MMT to install them. That way, you are just testing your local AMPs and you know those work and you have less to move.