I'll try and answer in order:
1) I believe you're talking about a loopback recording. Unfortunately this is not possible with the Scarlett series using Mix Control, it is a feature with the Saffire series however. There are external programs such as Soundflower that can create loopback inputs, or you might experiment with a cable set-up of plugging your outputs to your inputs, however from the description of your setup above, this may not be possible. You also have to be careful about creating feedback loops in your DAW.
2) I'm not quite sure what you mean here, If you're looking to send a cue out of a different output to your main outs, normally this would be possible through your DAW. But yes, normally creating a different mix for your headphones, generated by your inputs, would be created within Mix Control. I don't know of any other 3rd party programs that can capture that output audio and redirect it to specific outputs.
Hope this helps, please do get in contact if you have more questions.
Simon // Focusrite Technical Support