I like the ideas, though most of them are already implemented. Arrows can be used as a stabbing weapon, chairs and theoretical frying pans could already be used as weapons, it makes no sense to stab someone with something three times your size that in the actual game isn't even technically a sharp weapons, the rest of the stuff is planned to be the kind of random magical abilities you get on artifacts.
My point is a unified framework would cover all the use-cases effectively and allows for expansion by Toady and modding by the players. For example !!crundle!! pointed out that allowing interactions to be associated with items would also allow for mundane interactions (slapping someone with a glove to challenge them to a duel, removing the hat as a sign of respect, throwing a shoe as an insult, etc.). Right now, improvised weapons just get a blunt attack based on their weight (I think) and use the misc. weapon user skill. If workshops eventually had tools associated with them, you could have a smiths hammer set as a tool for forges, but then also give it an attack that uses the hammer-user skill and get a blunt attack. A carpenter's or mason's awl could get a stabbing attack associated with the knife-users skill. And so on. A single generic item framework covers all these cases the best.
My best example:
A knife can cut could food in the kitchen ( workshop tool), whittle wood in a carpenters workshop (workshop tool), whittle wood as an off duty hobby (personal tool), cut/stab in a direct attack(melee weapon), be thrown in a ranged attack (ranged weapon), be worn or used symbolically in a cultural custom (fashionable clothing/cultural interaction), be used in magical rituals (magical interaction), be used for surgery (personal tool), or be used as a utensil (personal tool). Thus you want one single category of items with raw tokens indicating usages to make this work.