I agree that it is impossible to completely imitate (La)TeX in Word. If you just want the font, then there is an OpenType version of Computer Modern, the default font of TeX. If you want the margins, just measure them on a LaTeX document and then set them in Word accordingly (I would recommend that you use KOMA Script or memoir as a base, not the default LaTeX classes, as the look imo better on A4 and letter paper.)
There is also a LaTeX template for Word. Since I don't own Word, I can't tell how good it looks.
I would consider (La)TeX to be ideally suited for exactly the purpose you mention. It is definitely flexible in the sense that you can follow a very basic approach of typesetting simple elements (you mention paragraphs and figures), and tweaking the layout at a later stage (table of contents, margins, stock-size). The latter is typically obtained via the addition of packages in your document preamble that enriches the document's content.
Perhaps, as a start of why to choose (La)TeX above other alternatives, you could read the CTAN: What are TeX, LaTeX, and friends? entry. Listed there you'll see the "reasons most often cited for using TeX, [which may be] grouped into four areas: Output Quality, Superior Engineering, Freedom, and Popularity."
Even if your eventual output is void of mathematics, the output and layout (in my opinion as well as yours) is "legendary". Perhaps, just to start you off of seeing what is possible, consider reading up on the memoir documentclass by reading the documentation. Others will definitely suggest other styles and flavours, giving credit to the flexibility across many platforms. memoir also provides sufficient functionality to mould the page sizes and layout in order to "stick to certain strict [publishing] rules". However, other options also exist by means of the geometry package. Consider reading the package documentation - it provides a rich mean of configuring your paper stock, trimming margins, text block, headers, footers, etc.
From a very basic point of view, your document would have the following structure:
\documentclass{book}% or \documentclass{memoir}
%<preamble filled with packages and other goodies>
\begin{document}
%<your future lulu.com masterpiece>
\end{document}
Like anything, you'll have to get used to the way things work in (La)TeX, just like you originally did when you fiddled with typesetting in MS Word. But there is a multitude of resources out there to help (from this Q&A to the comp.text.tex forum, to the CTAN). Also consider, as a taste test of some future possibilities, viewing the TeX Showcase.
Best Answer
I would not be satisfied with Word-like layout, and my opinion is if I use
typeareaorgeometryI can get optimal results. Either I decide layout division (typearea) or specify the exact margin values (geometry), so the layout is in my decision. I agree that LaTeX's default values might not be good for everyone, however it's easy to customize.However, there's a package you might like, it's called
wordlike. It offers narrow margins, makes Times, Helvetica (Arial like) and Courier default fonts for Roman, sans-serif and typewriter font, respectively, and it makes\sloppytypesetting.