No. With Atlassian Marketplace, you can install the add-on from inside of your JIRA server using your browser. You don't have to go to the server command line to copy files or configure XML files.
For the most common setups, the URL to your Git server and credentials to access it. Tell your Git administrator that you need access to the Git repository just like a regular developer would have. They will provide what you need.
A new tab is added in each issue.
A new tab is added in each project.
Atlassian has posted the following relevant information regarding Atlassian Marketplace addons and development licenses of JIRA:
Which points to:
Go to the section titled, "Can customers use developer licenses for my add-on?", which has instructions on how to get a developer license for add-ons.