If I click "Save and continue" -- should it publish the post?
ETA
Yes it published it. And only afterwards the drop-down list with an option "Drafts for XiXiDu" appeared.
ETA #2
This is a bug, don't punish people with downvotes for publishing their unfinished drafts.
People don't expect their draft to be published when they click "Save and continue" if there is a "Submit" button.
I agree with AndrewHickey that using a text editor is best.
If you are really averse to writing HTML by hand though, there is Amaya, which is a web editor/browser that should generate very clean HTML if you don't explicitly set style properties. I haven't used it for years though and can't easily install it on Linux, but anybody on Mac or Windows should be able to install it fairly easily.