Passiv skills questions

Hay i got a few things on my mind that i would like an answer to.

1. Does the Inner force skill (18% effect of buffs) and others alike give a bonus to auras? or does this only work for stuff like molten shell?

2. will Sweep, Ground slam and auras work with the talent Amplify (12% increased radius of areas skills 8% increased area damage)

3. Buff and debuff duration passivs will thay give bonus to endurance orbs? or what will this one effect.

4. Will the support gem increased area of effect work with auras? was thinking of a 4L item 2x aura 1x area of effect 1x reduced mana.

to 4.
Yes Increased AoE can be used with Auras, but it's hardly worth it, as auras area of effect grows with leveling the skill gem.
to 3.
No Charges are not buffs they are charges, there are specific passives for the different charges, including a few that add charge duration.
to 2.
Yes, Yes and Yes, the Gem reads AoE it is affected by AoE improvements like
Amplify and Blast Radius.
to 1.
Sorry I don't know, and don't want to give wrong information, but according to
http://en.pathofexilewiki.com/wiki/Buffs
Yes Aura Buffs are affected by that passive.