Just a quick clarification - the icon must be 16 x 16 pixels, correct? Can I scale down a bigger pic by modifying the img tag? example ->
Not that it matters much since my submission is 16 x 16.
No, I would say not because then the image isn't actually 16x16. You have to manually create your 16x16 image, or scale an image you created down to 16x16 in an image editing program. And remember, it must be completely your own work.