Here are links to some studies on the value of neem, starting with one on the overall therapeutic implications.

Therapeutics Role of Azadirachta indica (Neem) and Their Active Constituents in Diseases Prevention and Treatment

Healing Skin Issues:

A plant-derived wound therapeutic for cost-effective treatment of post-surgical scalp wounds with exposed bone.  "CONCLUSION: This retrospective, non-controlled analysis supports ONE as a simple-to-use and safe treatment option for scalp wounds with exposed bone. Treatment costs compare favorably to those published for other treatment modalities."

Effect of Neem oil and Haridra on non-healing wounds.  "CONCLUSION: Topical use of Neem oil and oral use of Haridra powder capsule used in combination were found effective for chronic non-healing wounds."

Insecticide:

Efficacy of neem seed extract shampoo on head lice of naturally infected humans in Egypt 

Ovicidal effects of a neem seed extract preparation on eggs of body and head lice.

The efficacy of neem seed extracts (Tre-san, MiteStop on a broad spectrum of pests and parasites

Neem toward the ideal insecticide?

Neem cake as a promising larvicide and adulticide against the rural malaria vector Anopheles culicifacies

Ethnobotanical uses of neem (Azadirachta indica A.Juss.

Observations on effects of a neem seed extract (MiteStop®) on biting lice (mallophages) and bloodsucking insects parasitizing horses.