I haven't actually gone and summarized Indochina under each dot point heading... but I'll try and help.
* the nature of political, social economical and military policies within sth and nth vietnam and their consequences
Under this I assume you could have things like (for the South) the US backed Diem regime, Viet Cong infiltration into villages, strategic hamlets, US military programs such as the Phoenix program, WHAM, search and destroy etc, land reform under Diem... for the North things such as land reform, bombing... brain isn't entirely switched on right now. It's such a broad dot point.... that's what I found when I tried to summarize Indochina under the dot points, they are all so broad.
*the natureand impact of growing US intervention in indochina for both US, the peoples of indochina and the immediate region.
Well, when you think about it, the US really created this war. They had their Domino theory and containment and they inervened at Geneva to make Vietnam divided. Growing US intervention, in simple terms, led to more people being killed!!! You can talk about the impact of US bombing and operations on villagers, the social impact of the American presence in South Vietnam (the economy boomed, changed society a lot), also people in Laos and Cambodia were impacted by US intervention.... the US really created the Pol Pot situation in Cambodia (it may have happened anyway, who knows, but by backing Lon Nol's overthrow of Sihanouk, and by abandoning Cambodia when Lon Nol's forces were losing to the KR, it catalyzed that chain of events)... the immediate region bit is a lil tricky... perhaps they mean China's involvement in supplying weapons to the VC, and China's links with Sihanouk after Sihanouk broke links with the US because when Diem was assainated he saw what the US did to their "friends".... as for the impact on the US of their growing intervention, there was a huge financial cost, as well as the loss of lives. Also the social unrest in the US post-tet and the distrust created in the American public after my lai/pentagon papers/watergate was revealed.
I don't know if this is really helpful or anything, I feel like I'm just rambling a bit lol.
As for the role of the Viet Cong, they infiltrated southern villages and initiated the guerilla war in south vietnam against ARVN and Diem's regime. E.g. assassinations of village leaders (who were appointed by Diem)... they really drove the war of attrition in the south pre-tet by harassing the US troops and using guerilla tactics. Since their numbers were so hugely decimated by tet the NVA took on more fighting in the south after tet, but the viet cong's role was quite huge!
Anyway, gotta go I hope this helps a little bit if you have any more questions, ask away!