Yes, that looks fine.
I'm also on a Mac and I mostly use just TextWrangler/Smultron (haven't quite gotten the hang of TW's particular regexp flavour yet) and KindleGen, plus the Mobi2Mobi tools to fix the metadata afterwards. Although plenty of people set store by Sigil, which technically produces ePubs but can be used to make files suitable for Mobi conversion.
A minor nicety you might want to have if your book is divided into sections is to add an NCX TOC, which will give the reader those flickable chapter marks in the progress bar. Although this might already be handled by the Calibre conversion.
For what it's worth, KindleGen on the -c2 setting tends to have tighter compression than Calibre usually does, provided you use the
Kindlestrip script afterwards. If file size is an issue (I've heard Amazon charges the publisher extra for the transfer over certain sizes), then it might make a difference.
My personal workflow was posted some months ago in
this thread here, if you're morbidly curious. Mind you, I use it purely to fix existing books I've acquired that have something annoyingly wrong with them, rather than to create distribution-quality works.