During the scene when the Professor is showing Cubert his dark matter engines from inside the ship, the engines labeled "left" and "right" are on the wrong sides of the ship. The "left" engine is on the left from the perspective of the Professor, but it is shown that he and Cubert are facing towards the rear of the ship. This is why ships use "port" and "starboard", which are the same sides of the ship regardless of your directional relationship to it.
In this episode Cubert is named as the professor's heir. However, in Anthology of Interest I it is revealed that if Leela were a little more impulsive she would have been named as his heir for being so impulsive. It's possible that the slightly more impulsive Leela triggered something that caused the professor to not choose Cubert as his heir. It's also possible Cubert did something that made the professor decide that he shouldn't be the heir. It is further possible that the professor simply forgot that he had already chosen Cubert as his heir.
The professor shows Cubert a Universal Translator device, which unfortunately translates to an "incomprehensible, dead language". Cubert says "hello" into the translator to test it, to which the translator responds, "'Bonjour'"'. This implies that the French language no longer exists in the Futurama timeline, despite being used on several occasions - for example, in the episode The Route of All Evil "Au revoir" can be heard. (Latin is a dead language and is still used today like Bona Fide, Et cetera, Semper Fi, and so on. You might want to rework your hypothesis.)
In subtitles of this episode, Cubert's name is spelled Q*bert (Closed Captioning is typically added by other companies any any typos and errors in the dialogue is usually due to not having the script for reference.)