Sean, in all of those scenarios, you may need to obtain email opt-in consent - even though they now exist in Marketo. Your legal team will provide the best advice. For us, as long as they are an active client (within 12 months), we can continue to promote relevant offerings to them (per our Legal team). And of course, always give them an option to opt-out completely in every email they receive.
Thanks for taking the time to respond Dan!