Hello MIT App Inventor Team,
I would like to request you to please delete all of my posts and content from my MIT App Inventor Community account.
Please remove all posts, comments, and other content associated with my account.
Thank you for your help and support.
Why ? and why have you already started deleting everything ?
I would like to delete all of my old content because many of my previous posts contain mistakes and outdated information. I would like to start fresh and keep my community profile clean and updated. Please delete all of my previous posts and content. Thank you for understanding.
You can simply correct those mistakes using 
I wouldn't worry.
You are either getting help from Power Users to present your extensions / topics in the best way for other users, or comments are being made which can help you make your extensions better, and this shows an interest in the great work you are doing. Other users pick up on this, and will see you as a good and reactive extension developer.