The basic edition is free, and has all the snap to alignments you’re looking for. The pro version ($100) lets you save as an SVG, PNG, or PDF, so printing what you make shouldn’t be an issue. It’s a lot more powerful piece of software than I expected it to be.
The best thing about Star wars is the world building. The expanded universe with the books, comics, and cartoons contain much better stories than any of the movies.