This project contains a number of rejected suggestions however.

1.2 “When stop sign clicked” hat block
This block would allow users to click the stop sign to run a script. However, the stop sign is designed to stop all the scripts in the project. With this block in place, more scripts will start when you want the project to stop, thus defeating the purpose of the stop sign. Regardless, there are workarounds for this block using the timer or ghost effect blocks; these can be found in this post.

This suggestion extends to any block that causes a script to be run as a result of the stop sign being clicked, not just the specific hat block below.

6.4 Live commenting or streaming
This refers to some system where you would not need to refresh the webpage to see new comments that are posted. Some Scratchers think this would be convenient if you are engaged in a conversation with someone so that the conversation moves more quickly (somewhat like how texting works). However, aside from the technological barriers this would bring, it would also put a greater emphasis on the social media aspect of Scratch, moving the focus away from the project-creating aspect. Indeed, project creating is intended to be the primary focus of Scratch.

Those were the only two I could find in the list. Besides those, I highly doubt the Scratch Team would allow you to open new tabs or redirect the user to different links. And I also doubt they would allow changing the pen quality, FPS, or allow projects to download files without your permission.