Blog image and composer issue

Issue 1: I would like the images we place in our blog to be centered and not have a border around them. See this post as an example: http://homehighschoolhelp.com/blogs/open-house-in-february-with-fun-treats-every-day-1. The borders are not part of the image, it is put there by the blog. Please tell me how to center images and remove the boarder.
https://dl.dropboxusercontent.com/u/5868019/STACK-blog_images_border.png

Issue 2: My Composer does not allow me to toggle between html and wysiwyg editors. This is what my editor shows:
https://dl.dropboxusercontent.com/u/5868019/STACK-editor.png
Here is a video:
https://dl.dropboxusercontent.com/u/5868019/STACK-wysiwyg_editor.swf

Issue 3: We would like to add dates to the posts on the blog homepage: https://dl.dropboxusercontent.com/u/5868019/STACK-blog_dates.png

Issue 4: Our preview always generate a 404 error: https://dl.dropboxusercontent.com/u/5868019/STACK-preview_404.swf

Thank you,
Matt Binz