Should I have "installation" feature / scenario?

I'm creating BDD tests for a shop-system plugin. Before plugin features can be tested, plugin has to be installed in shop's admin page and configured on additional page.

1. Should I create "installation" feature / scenario? If yes, should I make every other test dependent of it?


2. Should I make the installation and configuration a part of "Given that plugin is installed"?


3. Should I assume that plugin will be installed and configured properly and I should not test it?


4. Should I create "reinstallation" feature, instead of "installation" to make feature independent?