There's only so much you can do to prevent someone from stealing your work, regardless of the format you provide it in. For digital content, the most difficult to circumvent is DRM (Digital Rights Management), but this is expensive. Adobe's solution is their LiveCycle Rights Management server-based product, but you can find other DRM solutions for PDFs.
Other approaches are to sell only after you have a legally binding agreement with the buyer where they agree not to distribute it, and.personalizing the documents with something that identifies the buyer (e.g., their name in a footer on each page.) This can be circumvented too, but it may help.
This is for a teaching products site that I upload to. So I don't think either of these solutions would work.
So are there any ways that are better in making it more difficult that the average person could do?
Is saving as a jpeg even worth the bother to flatten it besides securing with password with Pro XI?
I just don't want to make super easy for them. I have Jing and Snap shot for making previews one for taking a picture and the other one for bluring for the previews and thumbnails. Photoshop is much to intimidating for me to work with I wouldn't use much of it and overpriced. Not user friendly. Looking for easy programs that would allow me to make it hard for thieves to edit and and sell as their own.
If you convert to an image (JPEG), it won't really make a difference. If someone is going to go to the trouble of removing the security then that won't stop them. Even if a simple password could prevent copying, as long as printing is allowed then it is relatively easy to steal the work, as you mentioned earlier.