Could I perhaps suggest your site saving the post as a draft
This would be a good idea if possible, but until such a thing is implemented (which very well may be never), I'd suggest
anyone creating a substantial post while still under newbie restrictions create the post in a text editor or word processor. Then copy and paste into the forum. That way if the post is blocked, you have a draft that you can re-copy from again later.
I always copy the text of any long post and paste it in notepad or wordpad before I hit submit. This will save you a lot of frustration, believe me. I have notepad and wordpad pinned to my start menu, they come in very handy.