integrating membership 2 & marketpress with external events plugin

Hello,

{my apologies if this question is a bit out of place, I'm really happy with your service and plugins but some just do not meet the needs of this client}

I've been trying to change my event plugin to events+, however, unfortunately, it seems at the moment I might not be able to do this - events will be operated by the client in the near future and the editor is not very dummy-tech friendly.

I'd like to be able to continue using your plugin but in order to do so I have to find a way for the membership and marketpress plugins to integrate with the events plugin we're using.
how do I integrate this to another events plugin?
I'd like to have it so users have to log in in order to purchse tickets, but be able to view them even as a visitor (unregistered and not logged in).

what would be the best way to do this?
the plugin i'm using is the events calendar by modern tribe

thank you