First off, can someone explain to me why sling is 1+? that implies you need one hand to hold it, and a second hand has to do something to fire it. (You need a free hand to load it, yes, but not to fire it, assuming we are talking about Shepard slings.)
Second, Reload says you can regrip the weapon as part of loading it, but it doesn't say anything about releasing the weapon as part of loading it. So unless you have a third hand, it looks like Light and heavy crossbows have an action economy of "Fire, Change grip, Reload"
Which means it takes 2 actions to fire and reload a hand crossbow, 3 for a light crossbow, and 4 for a heavy. Is that correct?