3 Magic Weapon Spell Questions

[Beerf]

The spell is in the PHB, and read as fallows.
“Magic Weapon: gives a weapon a +1 enhancement bonus to attack and damage rolls. If you’re a good cleric, the cleric of a good deity, or a paladin, the weapon is considered blessed, which means it has special effects on certain creatures. You can’t cast this spell on a natural weapon such as an unarmed strike.”

1. Does this +1 stack with, let’s say, a +2 magic weapon, making it a total of +3?

2. What are the benefits of the bless part of this spell?

3. If the answer to question 1 is "no", can you still use this spell to get the benefits of the bless part?

 

[dcollins]

1. No. They're both enhancements -- see stacking rules PH. p 152 or DMG p. 177.
2. There are monster-specific weaknesses -- for example, see rakshasa weakness on MM p. 154.
3. Yes.