Tiffany Hardrick and Keith Sanders are accused of ending the school's contract with a bus company without board approval.
The school plans to add two more grades next year and boost enrollment from 181 to 240.
Former board president blamed for agreeing to a vague deal; current board says it won't try to get the money back.
More than twice as much of their income, according to the Institute on Taxation and Economic Policy.
The incident led to Gisele Schexnider being banned from the campus of the charter school.
The immediate aim is professional development, but the union also wants to lay the groundwork to organize the schools.
Gov. Bobby Jindal has pointed to Florida and Texas as models for his plan to cut income taxes and rely more on sales taxes. But those states rely heavily on two taxes he dislikes: business and property taxes. Would Louisiana rely on a "one-and-a-half-legged stool"?