I also wanted to get them all on steam since that's where my library is.
take a look at https://support.steampowered.com/kb_article.php?ref=2219-YDJV-5557 ...
If you wish, you can add everything to your steam library... from open-office to outlook, along with all your game... if you wish, you can forget about the usual desktop and have everything in steam...
Well, you will need Impulse too but only for patch/update