HI Anna,
VikingOSX wrote: "Your bigger challenge is controlling the spacing between individual words with different font characteristics, and who on earth can read 9 pt type even with vision correction."
Easily handled by adding Ian's use of centering the text to Viking's avoidance of tables.
Using Viking's overall method, consider adding a set of 'center alignment' tab stops to the Ruler to align all words in a set of columns centered on those tab stops.
When entering each word on a line, press tab once, then enter the word.
Do the same on the next line with the translated words. Here's the result, using the first line of Ian's text (with invisibles visible to show the tab characters between words).

The words are spaced a bit more tightly than I'd do it for a regular example. The text used contains several very short words, and makes better sense if the whole line is included, so I made sure all 12 words were included on the line.
The ruler at the top of the page shows the location of the tab stops.
The blue triangle at the left is the left margin stop, the one at the right is the right margin stop. These are left in position.
Between the margins, the tabs need to be evenly spaced, unless you are going to organize the words (in both languages) into groups by length).
With both lnes of text selected, I set the number of tab stops I needed, placing each approximately where they would be when I was done.
Each tab stop is placed by clicking the ruler where you want to place a stop. All stops are initially placed as left tab stops. Double clicking the symbol changes the type of stop through a four type cycle—left, centre, right, and decimal. The tab stops shown as a diamond are centre stops.
After roughly placing the stops, you'll need to align them evenly along the ruler. To space them evenly, I added an arrow shape to the page, set it to Stay on Page to make it easier to position, narrowed and shortened it to the tree shape shown, then duplicated it several times to get as many copies as I needed stops.
I then placed two of the pointers toughing the ruler where I wanted the first and last word placed on each row, leaving the rest located below these two and horizontally between them (where they had been created when I duplicated the original).
Selecting all of the pointers, and making two trips to the Arrange menu, choosing Align > Top, then Distribute > Horizontally, lined them all up, evenly spaced across the ruler.
Reselecting both lines of type, I dragged each centre stop as close to its pointer as possible (the stops can be dragged only to specific spots in the ruler), with the result shown below:

With everything in place, the 'forest' of pointers can be selected and removed.
NOTE: Setting table on the two (or more) lines at the same time may also affect the font and size of type, applying the same font and size settings to both lines. you may find it more efficient to set tabs for each line separately, then either use option-command-C to copy the style from the French line, then place the insertion point into the next French line and press option-command-V to paste the style into that line. Repeat for all the Frenc lines, then coppy the style from the first English line, and paste that into each of the rest of the English lines.
Regards,
Barry