You picked some VERY controvertial subjects.
*What were the key factors from the 1970’s to 1990’s that allowed Airbus to rise to the level of a duopoly with Boeing?
Those are mostly psychological. Boeing considered Airbus a "thief" in "their" backyard. VERY few real business factors.
*What lead to the failure of the L1011 and DC10 programs?
You call 446 DC-10s and 250 L1011s built a "failure"?
*How has the Boeing 747 impacted global air travel?
Boeing 747 only changed the US air travel. Its "global impact" only exists in the minds of Boeing historians.
*How has the Boeing 787 transitioned aviation away from the hub and spoke model?
It didn't. Boeing 787 made absolutely NO change to any aviation model.
*Why was the American SST/Boeing 2707 never fully developed?
The government didn't want to spend money on anything that couldn't bomb the Soviets. The end. You are 3980 words short.
*Why was the Concorde a failure?
It wasn't. It flew for 27 years.
*What were the causes of McDonnell Douglas's demise?
Demise? After buying MDD, Boeing moved to their HQ in Chicago, all Boeing managers and directors were replaced by MDD ones, and Boeing's entire legacy and policies were replaced with those of MDD, including their "who cares!" approach to safety.
In my humble opinion, you are not researching. You are pushing a view on the readers/listeners. Before you observe reasons of an event, you should first prove that the event actually happened. Which wasn't the case in the topics above.
If you need a good topic, look into why aviation in the US is more developed than in other countries while other modes of public transportation are barely getting by. Aviation lobby, airports construction at the public's expense, etc.
No friendship, love or respect unite people as much as shared hatred.