the theory about a connection between sulfites and red wine headache has not withstood scientific scrutiny. about 1% of the population does have an allergy to sulfites (which is why products containing sulfites are so noted) but the reaction the 1% have is not presented as headaches but symptoms more typical of allergic reactions in general.
RWH or red wine headache is a real phenomena however. many obtain comfort from antihistamines like claritin or alavert. although that is not necessarily a cure as much as a treatment for those who are histamine sensitive.
as to the morning after hangover, my belief is that it is almost always to do with dehydration and/or electrolyte imbalances. adequate hydration during the consumption of alcohol can minimize or eliminate most of these after-effects i have found. problem is, when people go on a binge to drink a case of beer or a couple bottles of wine on their own, staying hydrated is rarely on the agenda.