Hi Christine,
Yes, those are the only options for form follow-up behavior using the regular Marketo interface.
That being said, if you can write Javascript (or have access to a web developer), it is possible to further modify the form follow-up behavior.
The Marketo Forms 2.0 package has a Javascript API, which allows you to alter its behavior using a script on the landing page. There are many examples and an API reference in Marketo's developer documentation:
http://developers.marketo.com/documentation/websites/forms-2-0/I can confirm from experience that your specific requests are possible, and I can provide some additional guidance if you are willing to dig into the code. However, I would also advise running this documentation by an internal web developer.
Best,
Kyle