User Permission & Service Task

Hi all,
I come from other software that uses bpmn 2.0.
I've installed all the environment locally to test it and read from the documentation, however I have the following problems:

1. I cannot view all tasks with my admin user. So, if I create a new process with user tasks that aren't assigned to any group or user, these doesn't appear in the "Tasks" page. That's normal or I can modify some permission to view also these tasks?

2. Which is the standard way to develop a Java class and register this in a process as Service Task? I followed the few things written in the docs, but they seem too manual considering the case where I may have to develop dozens of service tasks