question2: Our custom code is -NOT- using editable templates. How do I get marketo forms to show up on the page?
All the examples/guides I've seen on the net in relation to the question involves editable templates. We are still using the pre-6.3 (or is it 6.2) (static?) templates. Suggestions (which could be a link) on how to solve the question?
Embed component comes default with recent AEM maven archetype project which inherits from Core component - core/wcm/components/embed/v1/embed
Given that you couldn't find, create a proxy component in your project code base inheriting from core embed component with project specific component group.
Ans to question2:
Once when you have set up marketo cloud configuration as mentioned in the doc, you can include your embed component in desired page(like how you include any new component to pages created using static templates) -> Include marketo in "Allow Embeddables" in Design dialog of the component in Design mode -> then author the embed component as illustrated in the GIF in Edit mode of the page.
Note : Configuring Policy for a component in Editable template is equivalent to configuring Design dialog of a component in Design mode for static templates.