I'm no expert, but, a therapist cannot ethically share anything about a client to anyone -- professional or personal -- without written consent to do so. So any diagnosis will not go into your medical chart without your consent. If a client is a threat to themselves or someone else, then yes, absolutely the therapist can report that client to the appropriate authorities. They are actually obligated to do so.

Talking about violent video games is not a valid reason to report someone. Getting caught smoking weed could land you in a little trouble though if you live in a state where it is illegal to partake in, obviously. And under no circumstances should a therapist be telling your spouse what you do and do not like. The dialogue in the therapy room is 100% confidential (with the exception of that whole threat to harm thing) so your T should not be telling your spouse anything unless you gave T written permission to do so.