First impressions are important, and one specific restriction SE places on new users can easily lead to a very bad first impression (see here for a recent example). If you add more than two links or any image to your post you'll encounter the following surprise when you try to submit your post:
One aspect that leads to this very bad first user experience is that there is absolutely no warning about this before hitting submit. The first time you're notified about these restrictions is when you already did all the work of adding links or images. Then you have to do even more work and break those links and images again, just to be able to submit your post. I wouldn't be surprised if a lot of users just give up and don't post their answer.
You also can't just put the links as plain text, they'll be automatically converted to links in most cases (if the
http:// is present) and you'll be stopped from submitting your post. To avoid this restrictions new users have to either completely delete the link or obfuscate it in a way that breaks the link detection.
Users should be warned the moment they want to add too many links or any image, the link and image buttons in the editor should also be disabled when using them would cause the users to run into these restrictions. New users even get the same Markdown explanations directly in the editor that mention how to insert images, but not that they actually aren't allowed to do that. There is absolutely no hint that image uploading is not possible for new users, before you hit the submit button. On the contrary, it's a prominent feature with its own button on the toolbar and a whole tab on the Markdown quick help.
Another very problematic aspect of this restriction is that it hurts those new users that are making an effort, it doesn't hurt users that just post crappy one-liners as answers. On Skeptics specifically, users that have observed our site and understand our citation requirement will inevitably try to include several links in their answers and fail. We're punishing exactly the kind of user we want to attract to the site. If a user tries to emulate the way our top users answer on the site, they'll run full-speed into the link limit and might get discouraged from posting there ever again.
Now, I've tried to convince SE to remove the link restrictions from Skeptics and also started a discussion on whether this restriction makes any sense anywhere in the SE network, both unsuccessfully so far. So while I still want this restriction lifted, reducing it's negative impact would be a good first step.
The image restriction is understandable, I think it would be a good idea to just disable that functionality for new users. Instead of the image upload dialog, they should get a notice telling them that they need 10 reputation to post images.