Instead of posting and then deleting, you can save your answer in a file on your computer, and continue editing it there. Then, when you're ready, paste it here and post.
Here is a markdown editor app for Google Chrome that will save your document in the browser.
One option might be to publish, then delete your post. When you are ready to proceed, undelete it, edit and republish. Would be good to hear confirmation from a moderator before you try it with a lot of content though :-> (users with more than 10k reputation will be able to see your post but not to vote on it - so maybe good to put a quick note at the ...
Community Wiki isn't a specific page; it's a status. Posts that have been edited a lot,1 and questions that attract a lot2 of answers, are treated as community-owned and are automatically set to CW. This change allows anybody to edit (bypassing reputation requirements). It also ends reputation changes for the original author, as it's now treated more as ...
You can limit your site-wide searches to CW posts using the string wiki:yes (or wiki:no for the opposite effect) in the standard search bar.
You can find out more about Community Wiki posts in our help center or in the MSO FAQ.