A single quiver holds a maximum amount of 250 bolts. Arrows used by Bows cannot be fired from a Crossbow.
Any Skill that may fire an empowered arrow may do so with a bolt as well.
In Diablo III, projectiles similar to bolts (but considerably larger) can be seen being fired from Sentries and Demonic Ballistae. Crossbows and Hand Crossbows can be used with any Quiver freely, but lore-wise, fire modified arrows, different in size and weight from normal ones.
In all three games, many spells that fire magical projectiles are commonly called Bolts; examples include Holy Bolt, Fire Bolt, Ice Bolt, Poison Bolt and other variants. These are not related to actual bolts, and do not require any bolts to be cast.