Is there some way to ask all drupal.SE admins to temporarily delete a post so I don't have to find Tim specifically?
Yes, there is. Just flag the post for moderation attention, and report exactly the reason for flagging the post.

There would be just a problem when the question is undeleted, but in that case you should
- Flag one of the posts written from the same user, and using the custom reason, explain that the previously deleted question can be undeleted.
- Contact one of the moderators using their Drupal.org contact form.
- Open an issue report here, although this is not preferable, as it would create too localized questions.
It would be awesome if the stackexchange site could say "It looks like this question might be a security issue, consider if you should report it following the process as http://drupal.org/node/101494"
I can add a sentence about security issues on the FAQ, and ask that similar information is added to the block visible to who asks new questions.

I can also add a specific question between the ones tagged faq on this very site about the same topic, and the procedure followed in these cases. This doesn't assure the users would stop to report security issues here, but it can help.
The questions still need somebody who verifies the topic is not about possible security issue, but we have the full community of Drupal Answers that can help with this.
Is deleting the right thing?
We have a procedure to follow, in the case a user posts sensitive data, and that procedure includes deleting the post. That is a procedure that is required from the user who posted such data, not from a third person.
On Meta Stack Overflow, I found I need to remove a question with sensitive data? which is the closer question I could find on Meta Stack Overflow.
I have been notified that I cannot post this information anywhere online and I need this question to be taken down. I have edited the specific information out of it, but the revisions would hold the information.
While the question has been asked from the user who posted the question on a Stack Exchange site, the accepted answer given to that question is the following:
Use the "Request Moderation Attention" flag option and explain your situation. (I have done this for you already.)
Another answer says:
After reading Remove a page or site from Google's search results I saw that it was possible to ask google to delete a page from its index faster than usual:
The URL removal tool is designed for URLs that urgently need to be removed, such as URLs that accidentally expose confidential data. If you recently made changes to your site, Google's crawlers will see this when re-crawling URLs, and any outdated pages will naturally drop out of our search results over time. There's no need to request an urgent removal.
I then went to the URL removal tool and filled a request on your behalf. Since the page has already been taken down (returns a 404 code) anyone can request an urgent removal. Its status is currently "Pending".
EDIT: I checked it and it shows up as "Removed".
As on Drupal Answers questions about bugs are off-topic, a question about a security issue discovered on Drupal (or any project hosted on Drupal.org) should be considered off-topic, and closed; once it gets closed, it can be deleted (which happens to any question that is blatantly off-topic, not constructive, or not a real question).