shinkan Never bother about what you are good at. I even give WIP files with my assets, so that people understand how I design them and also put up the videos on my online portfolio.
It doesn't matter if you show these things, because you will keep making assets and other packs and by the time someone either tries to steal or come to your level of skill set, you will be way far ahead.
Keep sharing that makes your clients appreciate your skill set.
Animations and Audio are different story.
Yes people will try to buy and put assets online on torrents and other sites, we just need to keep a tab for that and notify the store or the site to take them down, which can be done by just creating a google alerts of your pack names. As anybody uses same or similar names to upload on torrents, you will get an alert in your email.
And even torrents should't bother us because people who don't want to pay go to these sites. Genuine buyers always buy and they will keep buying from you in future. Instead piracy can actually help make your/ brand name famous if your assets are really good.
So according to me demo urls are really a nice way to give your clients even more than what they paid for.