MW13, it is not so simple, since the bottom line is what would the sheid do? Give someone a potch? Take away his parnasa? What is the sheid doing that the RBSH is not doing directly.
In other words, what does the sheid add to the old concept of schar vaonesh? If somebody falls into a pit, why say it was some putative sheid that pushed him there. Why not say Hashem caused him to trip? Is there any way to detect the presence of a sheid? If not, can they add any info to our understanding of our world? Give me a hechi timtza where something happens that could only be explained by the existence of a sheid. I.e., an occurrence where clearly Hashem decided to operate via a sheid, rather than through nature.
For example, somebody chas vshalom loses his job. We generally say, Hashem made the boss decide to fire him or lay him off because business was bad and he could no longer afford to pay his salary. Is there anything to be gained by saying, Hashem told a sheid to transmit a message to the boss to lay him off. What has this second scenario added to our understanding of the situation, and how would one distinguish between the two possibilities? If one cannot, then do sheidim really exist? What is the operative definition of a sheid?