No problem, just the forums being themselves. Inline images were never allowed since this package went up. The character thing is dev's paying the price for nearly a year of rampant spam and the steps needed to get it under control.
If you must share an image, upload it to a server and add the link here - oh wait...most are blacklisted, so you'll need to break the url, like this:
h t t p s : / / cnn.com
As for the invalids - see if wrapping them in code brackets via the editor helps.
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