Of course, that's the point of the account to share logins, you still get your own user with your own lists, recommendations and all that. Though, Spotify handles it nicer where you can add your own account to the family group plan.

Not often, but often enough to become a nuisance with 2 TVs or so, some tablet/laptop for school work/gaming/whatever and a mobile device per person.

Yeah, I think that's about right.