In our case, the marketing emails will cancel based on the status of the lead or contact in Salesforce.
The sales rep also has the ability to add on specific campaigns (for example to warm up other contacts in an account).
I think the easiest way is to set up your modeler, then when they reach a certain stage (IE Opp opened stage), you marketing suspend them. If you have this happen automatically in the background of your system, it ensures everyone is having the same experience. I don't recommend having reps do this manually through campaigns in MSI.
Also to clarify-- a blacklist is people that are competitors etc. who should not be receiving content. Two things should be going on with this: 1) a smart campaign should be set up that's 'listening' for typical blacklist people coming in that's automatically blacklisting them and 2) there should be a way for reps to manage 'bad data'. I've normally had this as part of the lead status field, but you COULD have it as a campaign within MSI, it just depends on how your team uses Salesforce.
Marketing suspend is when you remove people from mailings because they've entered a certain buying stage (or other behavior).
Regardless of how you do this, i suggest making it manual and not having it automated with modeler or stage, if you are trying to make sure the reps know that marketing is not communicating. A very clear field or campaign (Marketo add to campaign functionality) that says something like: No Marketing for 30 Days. This way they are super clear about what is happening and aren't upset when a prospect doesn't get a communication.