Kindle Previewer is not available in linux, but according to what I've read should run easily in WINE.
Personally, I'd check the book on my Kindle rather than in Previewer. And if the book is properly-formatted and doesn't have anything complicated in it, it's probably going to look all right.
Disclaimer -- I am a dabbler, since I fall strictly on the reader end of things, and Hitch would probably take my head for saying something so unprofessional, so don't take my word for this.
I believe the experts here would recommend a workflow of Word DOCX ==> Toxaris' addon ==> EPUB ==> kindlegen ==> dual mobi. Libreoffice can also be used, with
writer2epub instead of Toxaris' addon.
In between EPUB and kindlegen, do any editing how and when you like.
Question: When your friend converted your WinXP computer to linux, did he leave it as a dual boot computer? That means both Windows and linux are installed, and when you turn on the computer you can choose which to use. It's a pretty good option if you need to run a few Win-only programs. It's what I do if I convert a computer.