Q: When listing, items are having big fonts that overlaps with the pictures or other words.
A: The issue is due to the extremely large images within either the title section and/or the description at the supplier.
The only way to avoid something like this would be to put something into your bad words filter that would cause the images hosted by Amazon to actually break. In which case, you would end up with "broken thumbnail images" where the images were but at least it won't look like horrible text because the images were so big that they break your template.
Here's an example of how that would look:
If you prefer to break the supplier images so that they don't appear in your listings, you can go to your Bad Words Filter in your Filters & Formatting Settings of Sku Fetch and add media-amazon to your bad words filter. Since that's a part of the amazon image urls, Sku Fetch would then remove that part from the amazon hosted images and the images would be broken, not appear in your listings and not break your template. You will just see those little thumbnails as shown.