Hi Hive account@shadowgem maybe I can give you a little help ;) I don't think it's possible know to use colors fonts don't forget Steemit is also in beta.
When you write your story you have 2 choices editor or markdown you have to choose one for a few days it's not possible to switch between the two into a story.
When you are on the editor mode you can't see the preview and you have option above for italic bold etc... Editor don't support markdown.
When you are in markdown you have to use * and # like you said and you can use a little bit of html too. And see the preview ;)
If you want to make a link use [yourlinkname]+(intenetLink) without the "+" and no space.
I use imgsafe.org to host my pictures when it's done I just have to copy/paste the link after upload.
If you want to center your pictures you can use < center > imagelink < /center > (without the space for < center > and other too at the end dont forget the /)
you can use < code > your text < /code > (without space)
For embed link (for video) use youtube when you upload your video clik share under the video and you can find the embed link.
I hope I help you ;) sorry for my english (not my language) if you have any question ask me and welcome on Steemit!
Hive account@pickoum