Enevhar Aldarion
Hero
Aaaactually, a +1 weapon only has the same requirements:
"You have a +1 bonus to attack and damage rolls made with this magic weapon."
Using it as a foci still means attack and damage rolls made with it.
As does chucking it at someone, say as an improvised weapon.
Not in any group I have ever been part of, from 1st ed AD&D through 5E. You only get the bonuses when using it in the way it was intended. That means hitting someone with the blade of a sword or firing an arrow from a bow. Especially the bow, since it's magic is instilled into the arrow so that the arrow is counted as magical when it hits a target. The bow itself is not a +1 club when not shooting an arrow from it.