Hypothetically the Germans are able to set aside their inter-service bickering to come to a inter-service plan on starving Britain into submission, how would this play out? This would replace Sea Lion as the primary plan to bring Britain to the table, assuming that it was ever seriously considered.
My proposal: The Germans set up a purpose trained combined service (Luftwaffe-Kriegsmarine) air unit that handles the air component (aerial mining, torpedo attacks, reconnaissance work for subs, etc.), as Helmuth Felmy advocated prewar, while the Luftwaffe and Kriegsmarine have their own tasks. LW bombs ports exclusively, especially Liverpool, which was the primary port for intercontinental shipping. Obviously the KM focuses on sub and surface raider attacks that pass north of Ireland (the primary route for convoys).
There are several changes though: FW 187 is chosen instead of the Me 110 for long range escort work
http://en.wikipedia.org/wiki/Fw_187 , there are purpose build torpedo bombers built for this unit
http://en.wikipedia.org/wiki/Fieseler_Fi_167 plus He 111's and Do 17's at aside for mine laying and torpedo bombing operations, there are long range recon craft available for work with subs (I'm thinking Do217 and various flying boats with 2,000+ mile range like the Do 22 and BV 136) specially trained for open sea navigation/vectoring. The Ju 88 is only used for bombing operations, including those at night if losses during the day are too high.
Also there are tactical changes: the magnetic mine (first produced in 1939) is not introduced until 20,000 can be build (i.e. mid 1940) and are only deployed as part of a concerted effort by planes, subs, surface ships once bases in the Low Lands and France are available, concentrating their use in the Thames Estuary and near Liverpool. Previously only contact mines are dropped by aerial units/laid by ship. Also the full plan doesn't go into effect until at least France is dealt with. No switch in focus, just unrelenting pressure in closing British ports and shipping.
What is the outcome if such an effort is undertaken in August 1940? Personally I think it would strike directly at the heart of British vulnerability and could cut off the most critical resource that would force Britain to the table: fuel. A focused effort to destroy trade will be bloody for both sides, but the pay off is substantial. The big problem is whether losses can be sustained for long enough to fully bite into the British before attrition loosens the vice grip, allowing the Brits to stay in the war.