I stopped the bot for now and I agree I have to test it more thoroughly. I appreciate all the feedback so far.
I'd like to emphasize that I got this idea because I read many complaints on Steem about people taking advantage of someone else's content without permission. Maybe I should rewrite the bot's texts a bit, I see some people get offended by it (even though I never meant to accuse anyone of plagiarism), so it might need a different 'tone of voice'.
Again, thank you for your feedback. I wanted to test the bot as much as possible 'in the open' and gathered many new insights this way. Now it's time for further development and I will update you all soon!