Bloody hell Dave, that is a master class and a half!
Some excellent stuff there that I hadn't fully appreciated before.

Scotty, the short answer is no I'm afraid. I can enable bmp's period, but to set a size limit would require a vast ammount off coding which even then would only be valid if the site uploader was used as there is no way of verifying the filesize of an external (hotlinked) image - it would just load it whatever.

To enable bmp's however would take at least 50-60mins of my time to do & test, and to be honest I am not prepared to do that 'cause I'm a lazy bugger!

Not really, I'm just too busy doing other stuff I'm afraid, especially when you compare it to the time it takes to save the image in a different format