Very Insecure, Pretty Significant, Quite Irrational

It seems that the Harris Academy in Upper Norwood has banned some words.  Good for them.  I'd like to ban some words as well.  Here's some sentences I recently read in my students' essays:

• "I strongly believe the trip would be a pretty significant waste of money."
• "Basically, I find her reasons to be quite irrational."
• "I felt very insecure about my knowledge in that area."

Read the sentences again without the Italicized words.

Do you lose any meaning when you lose those words?

If a word doesn't add meaning, you know what to do, especially if you want to write better (dammit).