The "Create account" link isn't popping up the right-click menu because it doesn't use the Link widget. You'd get the same thing in plain HTML if you used a <div> with a custom click event listener instead of <a>. It's a simple bug to fix; totally up to the app developer. I think issues like that will inevitably pop-up as we have developers coming to the web from other platforms, where "open in new tab" isn't part of the toolkit. Perhaps it's fixable via education and platform-specific guidelines.
We're aware of the input blur issue. I think the bug is in the TextEditable. You can write your own, of course, but since we offer it as part of the Flutter framework, it's on us to fix.