Hi Dan,
So if I understand correctly, what you want is an editable H1 header where you can't put anything else in there. We're currently working on a feature right now that would let you do this. However, in the meantime, the only workaround is to only have the H1 button in the toolbar. Unfortunately, with the current version, if someone hits enter, they will get a <p>. This is unavoidable in the current version.
For the links, we had originally made the decision to make links behave as they normally would when the editor was not activated. However, in your use case, it seems like it is an unwanted behaviour. I will discuss with the team about adding a flag to the config to either allow or disallow the following of links.
For saving HTML, you need to specify an "onSave" callback. You can check out the docs.
The "e" that gets passed through has an "html" attribute that has the contents of SnapEditor. Using e.html, you can send the data to your server through AJAX.