Donald
I agree that HTTP authentication is the future. That is why I gave 2 x 1 hour lectures on this subject at a recent SAP TechEd conference in Bangalore. I described how our products can be used to implement this strategy. I recommend using an authentication product on the ABAP stack that handles HTTP auth so that products like Personas 3.0, Fiori, NWBC etc. can be supported, but SNC still has it's many benefits for both authentication and session encryption.
These are the reasons why I recommend short, medium and long term to go with option 1 or 2 and not 3 or 4.
Lets not discuss this anymore via SCN, since this thread is already too busy. If you have any need to discuss more, please contact me. Lets give Madhu a chance to ask his questions or add comments since this his his thread that have been chatting on.
Take care,
Tim