A 159 A) and B) In 3.0 (including BoVD), you could take a free action out of turn if the effect said so (see the initial wording of Feather Fall). This is the same with a grinding weapon. Both versions can (or could, in the BoVD case) be used with AoO.

C and D) The "normal" strength bonus is the strength bonus you would get by simply wielding the weapon normally. You get the x1 Str bonus from a light or one-handed weapon, and x1.5 for a two-handed weapon.