Hi,
Using extra segments in the urls like /blog/ and /gallery/ is not supported, see this document:
http://www.mojoportal.com/search-engine-optimization.aspx
you can use blog-myname or gallery-myname but not /blog/myname and not /gallery/myname
Images need to be uploaded in the editor if you want to use them in the editor so there is no point to adding a separate image upload button since then there would be no way to position the image within the content.
I do plan to add support for attachments so you could upload an mp3 or a video to make a the blog support podcasting or have download attachments, but these files will not be used inside the editor.
Best,
Joe