First of all you need to invite the bot, or else it can't do anything
All of the permissions it requests are purely used for the actions of this bot, we're not scraping your server's messages.
The source code for this bot is also available if you want to see exactly what the bot does, and you can even check which commit it's running on with the /version command.
Once you've added the bot, by default anyone can create a prediction, to change this you will need to manage the bot's permissions