The power of the attacking creature is checked only when the ability triggers. Once it triggers, Raid Bombardment will deal 1 damage to the defending player even if the creature’s power changes before the ability resolves.

If you attack with multiple creatures with power 2 or less, Raid Bombardment’s ability triggers that many times.

In a multiplayer game, the ability checks who the defending player is for each individual attacking creature with power 2 or less.

If Raid Bombardment’s ability triggers in a Two-Headed Giant game, the ability’s controller chooses which one of the defending players is dealt damage. The choice is made as the ability resolves. A different choice may be made for each ability.