My Improved Familar

[Quemar]

I took the Improved Familar feat, and I now have an small Air Elemental as my best bud. I have a few questions in what he can actually do:
1) Can he carry anything?
2) If he can carry stuff, can he drop them as well? I'm thinking of a flask of Alchemists Fire on the head of a troll from 20' up.
3) Can he throw things?
4) Can he manipulate things? Levers, traps, etc...
5) Can I cast spells on my familar to buff him (i.e. Bull Strength, etc...).
6) I know there is an "Augment Familar" spell, and if I cast this on the familar he gets a +4 con, among other things. However, if he is restricted to 1/2 my HP, does he gain any HP from that +4 con?

Thanks for any help!

 

[Sledge]

From the SRD we see the following

An elemental possesses the following traits (unless otherwise noted in a creature?s entry).
Darkvision out to 60 feet.
Immunity to poison, sleep effects, paralysis, and stunning.
Not subject to critical hits or flanking.
Unlike most other living creatures, an elemental does not have a dual nature?its soul and body form one unit. When an elemental is slain, no soul is set loose. Spells that restore souls to their bodies, such as raise dead, reincarnate, and resurrection, don?t work on an elemental. It takes a different magical effect, such as limited wish, wish, miracle, or true resurrection, to restore it to life.
Proficient with natural weapons only, unless generally humanoid in form, in which case proficient with all simple weapons and any weapons mentioned in its entry.
Proficient with whatever type of armor (light, medium, or heavy) that it is described as wearing, as well as all lighter types. Elementals not indicated as wearing armor are not proficient with armor. Elementals are proficient with shields if they are proficient with any form of armor.
Elementals do not eat, sleep, or breathe.

Anything not limited herein is okay so:
1) Anything a 10 str small creature can carry.
2) Of course, but I imagine he would have to make a roll to hit.
3) Not proficiently.
4) Yes
5) Yes, That is a basic ability of familiars to share spells.
6) Familiar HP is not "restricted" to 1/2 so much as set at 1/2 hp. I could however see a generous DM allowing you to roll the Familiars HP and use that when it is higher than 1/2 the character. In this case the +4 to con would increase the rolled HP and possibly raise it above the 1/2 character HP. Generous DMing is required for this however, as by the rules it doesn't affect HP.