Perhaps you're on an older version of FF, no? Because the things you mentioned are present, just not an exact UI/UX as that with Chrome.
Im on FF Quantum 57.0 (non dev, vanilla FF) and here are my observations:
> When an XHR response comes back as HTML, there is no "Preview" tab like in Chrome.
This is consolidated in the Response tab. You can view it as raw response, or JSON (with filtering options).
> Also, the responsive testing tool doesn't have the device frames (ie, iPhone, iPad, etc)
It does now! You can select and edit a list of device.
> and it also doesn't have the little touch circle cursor that let's you drag and swipe while testing.
They do have a touch simulation mode (pointing hand icon), but it doesnt appear to work at the moment. I cant drag the screen.
