One thing I really wish Sublime had and I don't think there is anyway to solve this via a plugin is an image preview. If you click an image, instead of seeing binary data, you see a preview of the image.
it should at least have an option to open the file in whatever program is associated with the file type. Or allow you to assign one.
I would much rather inline, this way you can keep on editing and if you need to know the image real quick you can see it but don't have to grab the mouse to work out of another app.