Hi there,
it is very annoying but unfortunately WordPress didn’t make it easy to change…. i use a desktop IDE and the browser dev tools when writing code, which means i only copy and paste to the Additional CSS if i am using it.
Images you need to provide a direct URL to them – eg. from your media library or shared from any of the image sharing sites. But dropbox links and the like, we have no issues with.
We use Gravatar for the profile pic:
https://en.gravatar.com