I have a character with variant tiefling ability #49:

You are healed by both positive and negative channeled energy.

Several spells state that You channel positive energy or If you are healed by negative energy then this spell heals you.

How do the following spells and special abilities affect this tiefling? What heals him and what harms him?

• inflict wounds
• chill touch
• harm
• repair undead

• channel energy when used to harm living creatures
• channel energy when used to heal undead creatures

Does having one or more necrografts affect this in any way besides dulling the effects of positive energy?