Occasionally a start-up may ask me to sign a non-disclosure agreement and it does make me smirk. It is commendable if you have one and if you feel you really need one then get one but in all honesty don’t waste a lot of time or money creating one.
The chances of anyone stealing your idea is super slim. Likewise the same goes for images and content. It can be stolen but its extremely
rare and the impact of the theft will be so small, its negligible.