Rather a nano- than a microprivilege:
Questions become immune to “tumbleweed” roomba deletion
Your questions are not affected by the following deletion ruledeletion rule anymore:
The system will automatically delete unlocked, unanswered questions with score of zero (or one if the owner is deleted), fewer than 1.5 views per day on average, and fewer than two comments after 365 days.
Rationale: If you managed to reach a high reputation, your questions deserve the benefit of doubt for being remotely reasonable. Thus, if they match the above criteria, they are likely to be difficult-to-answer questions on a topic so niche that people do not even look at the question.