First thing, you should not post your questions to the "Champions" group as you are less likely to get and answer. See Getting the most of the community when you have a Marketo question
- Yes, the revenue have to come from the opportunity object in order to be used in all the Revenu cycle reporting.
- There is an opportunity REST API. See http://developers.marketo.com/documentation/opportunity-api/ The key point is that it will be accessible ONLY if you have not sync'ed Marketo with SFDC nor Dynamics.
- The second hard point is that, for the moment, you cannot add fields to the opportunity object. AFAIK, you can ask support to add some.
- And vote here: Being able to add opportunity fields when not connected to a CRM
So I do not think there is really a solution that can encompasses all your requirements.
Thanks Gregoire. Confirmed my suspicions. Yep will post into "Products" from now on and ignore Marketo's "suggested" places to post.