There are two things posters do that make reading the boards a chore. They both extend scrolling length of the page. Luckily there are simple solutions to these problems.
1) Posters quote images. Find a way to disable the image tags function if they’re within quotes. That way the link only displays as plain text or a text link if someone quotes an image.
2) Multiple media (e.g. Youtube) embeds in a single post. I would say three or more embeds in a single post is overkill. You could automatically hide any post with three or more embeds as if it were hit with multiple flags/WTFs. Similarly, you could automatically wrap these links in spoiler tags so they have to be clicked to be seen. Lastly, you could just force all links to be plain text or hyperlinks if they exceed the limit.