Yes, unprefixed properties should go last. This is because CSS rules lower in a stylesheet have priority. In theory, it's possible for a browser's experimental (prefixed) implementation of a property to behave differently to its stable (unprefixed) implementation, so you'd want the stable property to supersede the experimental one, hence putting it last.

As for capitalisation, it doesn't matter in a CSS stylesheet but it does matter if you work with styles in JavaScript, so it's better to keep them lowercase.