On the first site you mention there are specific licenses for the images, as far as I can see most of the images are CC Attribution-NonCommercial 2.0, which means you can’t use them in your theme. You can check out this link for more info on the license - https://creativecommons.org/licenses/by-nc/2.0/
On the second site I don’t see any licensing for the images, which means they are most likely copyright protected by the author of the site, you can contact them for permission to use them in your theme otherwise they won’t be permitted.
EDIT: Actually on the second site the images are licensed by CC too but you can use them in your theme provided you give attribution ( a link to the source in your item description would be considered attribution in this case )
From the site: “In short, this means you can freely reuse and distribute this content, also commercially, for as long you provide a proper attribution.”
None of things you mentioned are necessary for getting your theme accepted on TF, it’s up to you to decide if you’re going to include these things in your design or not. Cheers