Ability to have users with or without teams

I need some advise to understand if Spark is the right choice as a foundation for this project:

Simple description: The site will sell tickets, book appointments and rent out exhibitorspaces on events.

Question 1

I will have two kinds of users. Those who belongs to teams and those who will not. Organizers will need teams and multiple subscriptions. Visitors will by tickets - with or without registering an account, (and never teams). Exhibitors reserves a space, must register but never as a team and never a subscription (free).

From looking at videos and reading the documentation it looks like all registered users must belong to a team?

I do understand that I can add any kind of code I want but I would like to know in advance if Is this an "easy fix" or will it be a major change of the Spark core so I'm better of doing it all from scratch myself.

Question 2

Does Spark come with user-roles and stuff like "if user can" based on roles?

Grateful for any advice.