Bounce information

Not typically.

It does record bounce details under Email Bounced Reason. You could try to sync it back by setting up a map or flow step to do so.

If a record becomes Unsubscribed=Email Opt Out in SFDC.

Here's my summary of what marketo does
http://www.slideshare.net/jdavidhill/marketo-email-reputation-management

@Robert if you sync over fields from Salesforce that indicate a contact's last sale date, you might set up a flow to add Tasks to have your Sales folks call the ones that are active but aren't reachable by email.  

I admit we don't currently do this... but we should!