I forgot to say the "author title" would be really hard to come up with something... So I got the only thing available, which was author's bio.
And the image width is set to maximum and so no, it won't appear as the file size. But the whole blog width have a max-width of 1140px, so the image will also be restricted to that only and given the current "one sidebar" layout it will make the image be a max of 840 by coincidence ( unless that's where you got the number from 
). We could add a max-width to the image, if you want, it's actually as straight forward as adding max-width: 840px on the .post img Custom CSS.
The current "footer" is actually a redundant header... But maybe I'm getting too technical. I've just changed it to the complete footer instead. And I can make it work on the whole website (so to any blog you make) anytime you want. I'm not sure this new design mock up is fine by you, though. Please let me know.
And I don't experience any slowness, in fact it loads quite fast here. It's definitely your internet connection, though that doesn't mean only exactly "in your end". It could be even a DNS issue on your internet provider, which usually don't last long.
