No, it will not. Your location will only be displayed when you are hanging out with one of your Nappsis friends.
Not really. Firstly, only those close friends that you decide to have in Nappsis will see you.
Secondly, you can activate the Private Mode in your settings to keep all your interactions private even for your close friends. In this case, it will be up to you which ones you make visible.Nappsis friends.
Good question! No it will not, to prevent Nappsis from saving interactions in specific places and/or with specific people you can use the exemptions.