Does anyone know if it is possible to obtain the required Affirmation to Marry - Marry a Thai National and apply for a Visa Based Upon Marriage to such Thai National, within the week?

Up to your Embassy. Most people seem to be able to do it all in a day or two with help. Maybe 3 or 4 without.

Surely the granting of a Visa Married to a Thai National would be up to the Immigration Office in Bangkok?

Surely the granting of a Visa Married to a Thai National would be up to the Immigration Office in Bangkok?

Nothing to do with Bangkok.

Get the Visa outside Thailand .. eg. Penang , KL , Singapore, Laos.. etc...

Immigration offices in Thailand give extensions of stay , not visas.

Edited October 26, 200718 yr by Lite Beer

Immigration office can issue visas if you qualify for extension of stay. But I suspect poster will have to exit country and use marriage certificate/copy of ID card to obtain a non immigrant O visa. He can also obtain a 60 day one time extension of stay immediately after marriage if he applies to Immigration.