"Capital" is the wrong word here. It doesn't include non-productive, consumable goods such as food, but it can include money as a stand-in for means of production. It doesn't make sense to contrast "capital" with "money" when what you really mean is "all goods which are not money".
In any case, the difference is utility. The value of money is (almost) entirely derived from its use in trade; it's not consumed and it doesn't directly serve as a means of production. If a factory burns down or food spoils then society is poorer for it, but if the amount of money in existence decreases then nothing of value is lost, provided it affects everyone holding currency equally. (In the case of someone dying the only one not affected equally is the deceased, who isn't around to object to the loss and thus doesn't count.) We still have all the consumable goods and means of production which we had before, and the purchasing power of the remaining currency will adjust to compensate for the change in the money supply.
Yes, but the dependency on what counts as a good cause also applies to distributing wealth indiscriminately among all holders of a currency.