If the activation of a Spell Card is negated by "Magic Jammer", etc., then you will not gain Life Points for "Spell Absorption".

A Spell Card used from the Graveyard by the effect of "Double Spell" is not considered "activated", so you will only gain Life Points for "Spell Absorption" for "Double Spell" itself, not for the card used from the Graveyard.

When you activate "Spell Absorption", you do not gain Life Points for activating "Spell Absorption" itself.

Super Polymerization: If "Super Polymerization" is activated while "Spell Absorption" is active, the player who controls "Spell Absorption" gains Life Points.

The effect of "Spell Absorption" is applied when the Spell Card is activated. You cannot chain to this effect. The effect is applied immediately. For example, when activating "Tribute to The Doomed" while "Spell Absorption" is on the field: (1) Pay the cost by discarding a card, (2) Activate "Tribute to The Doomed", (3) Your Life Points increase for "Spell Absorption", (4) Check for chaining and resolve "Tribute to The Doomed".The newest errata of "Spell Absorption" implies that its effect is applied "after" the resolution of the Spell Card. This makes this Ruling invalid.