WARNING! READ HERE:
This may be already rejected, though I am going to try any way.

Team Creation
If you want a friend to help you with a massive project, with collaborations, you can invite your friend to make with you. If someone tries to force Collab with someone with like a bad computer and can't handle many projects, this will be an easy fix.

Invites
Invites make it so you have to be invited to collaborate, meaning no bot spamming Collabs to overrun someone.

Toggle Setting
Players are able to make it so then they can not have any Collabs except the ones they already have.

This suggestion is rejected.

The Official List of Rejected Suggestions wrote:

2.1 Adding users to work on projects
Having multiple Scratchers work on the same project would be difficult to moderate not only due to technological limitations but also because it could lead to private messaging; for more information, see #7.1 on this list. This includes live editing (similar to Google Docs) and other forms of private collaboration. If you would like to work on a project with another Scratcher, you can remix each others' projects.

At the moment, a turn-based collaboration system for shared projects is NOT rejected. You can discuss it on this topic.

Make sure to read the Official List of Rejected Suggestions before suggesting another feature.

I understand.