You spoke a little about pebbles in the recent DF Talk.
1. How do pebbles as terrain work?
2. Is there a way planned to reduce boulders to pebbly terrain, or was that just speculating about what you would need to do if there was a realistic amount of stone?
3. Are there any plans to introduce throwing combat into fortress mode or would our military love throwing their clothes too much for it to be sustainable?
4. Is there any chance of brave civilians tossing pebbles at an invading force, or a hated noble?
1. Currently it's essentially just a description.
2. There have been talk about partially dug out terrain, such that clay and sand deposits run out. When/if that's implemented you'd be able to do landscaping by moving soil a bucketful at a time (to e.g. prepare for farming on a rock floor, or level out the terrain). At a guess you'd get 999/1000 or something sand in a tile after taking a bag, while filling a mine cart with rocky debris would make a larger dent in a pile of broken rock (if that's implemented: might be too tedious).
3. I would be less worried about thrown clothing than thrown weapons (that are not intended to be thrown. Possible scenario: The marksdwarves empty their quivers of bolts, throw their crossbows, and THEN perform a suicide charge with their fists (in the second iteration. In the first one they'd start by throwing the crossbow)... Throwing items would require a new logic that let the dorfs evaluate whether the item they wield or otherwise have at hand would be any good for throwing, and then weigh throwing items against bashing the enemies with them, based on both whether there is a supply of additional suitable items, and whether they actually intend to enter melee or run away after throwing the items (and attacking from range and then run away would be a new behavior).
4. If I wanted to hurt someone I wouldn't throw a pebble or a fistful of pebbles, but a fist size or so stone. When it comes to invaders, throwing rocks would be a new combat behavior (essentially 3), while attacking hated public figures with the intent of actually causing an injury or just show disdain would require new logic for the dorfs to get them to have such a behavior in their repertoire (and probably some interesting [more or less lethal] food fights in the tavern while the parameters are tweaked).