TurboTax's suggestion that supplies are usually less than $200 and last less than a year is just a guideline. There isn't a hard fast rule because each business is unique. A $500 item may be a supply for one business and an asset in another.
In general, after $200 and a useful life greater than one year, items begin to move into the asset section and can't be expensed in one year (they are depreciated). Even the example given in TurboTax 'reference books and guides' clearly can last more than a year. In addition, some professional books/guides can cost much more than $200.
As for miscellaneous items, this category exists for all other expenses that don't fit into one of the categories listed and are not assets. This can be anything.
You did not indicate your business above, but looking at your list you could put:
postage: office expense
cases/headphones: Misc
chargers/AC adapters, wires, tools: Supplies or Misc.
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