I would like to suggest a few changes for the new forum:
1. Having an Advanced search feature which would fetch results based on the topics created/replies of a particular user. It could also have an option to sort the results date wise and could be customized.
This is already there. See
https://bitcointalk.org/index.php?action=search;advanced.
Searching by date isn't possibile, however, you can use "Massage age" feature to sort according to days and it is enough IMHO even if we have to do a bit of work to check posts in a particular date.
2. Ability to have a post ID reflected in the "Show new replies to your posts." results . For eg: The results would reflect the Subject of the thread and the post ID/s of the user.
Subject and username is already in in, so is there a need for post ID?
3. Notifications via email for a feedback received.
I don't think this is needed.
the delete button of a post to select one or many posts and delete them.
If the posts you want to delete is in one page, you can check the checkbox in top-right corner of your post(after post number) and click "delete selected" in bottom-left corner. If the thread is small, you can use "All" view* to get all posts in one page and delete the posts you want to.
* All view can be done by either clicking 'all' or by appending ";all" to the url. For example, if this thread have 2 or more pages, you can get all pages by going to
https://bitcointalk.org/index.php?topic=1016451.0;all.