The Jedi are not supposed to interfere, something they do frequently regardless. Qui-Gon was already known to bend the rules but he wasn't so impulsive as to kill a slave owner that isn't attacking anyone under his care.
The Jedi Order was hypocritical and paranoid. Their hubris and arrogance led to their eventual downfall.
Literally the first thing we see Jedi do in episode one is get dispatched by Valorum, Chancellor of the Senate of the Republic to negotiate with the Viceroy of the Trade Federation (Nute Gunray) in an attempt to get him to disband his illegal blockade of the peaceful planet of Naboo per request of the recently elected Queen Amidala of the Naboo. They're the motherfucking CIA of the Republic. They're basically like if the Secretary of State had an agency of hybrid ambassador/spies. Their whole business is to interfere on behalf of the Republic. They're space wizard samurai cops.
Problems with the Jedi Order are more explicitly discussed in the EU of the series, especially pre-Disney. Iirc even Luke Skywalker finds something of a “middle way” in the force.
What kind of Trek-level “prime directive” nonsense is this?
Isn’t Tatooine supposed to be part of the Republic? It’s near enough for them to space limp from Naboo, and yet the entire Republic was dragged into war over Naboo. If Naboo can be held under Republic law, Tatooine ought to be as well.
Pretty sure Watto had to sell her to help cover gambling debts from anakin winning. I could be wrong, but it would have been fairly simple for the Jedi to send somebody out to take care of it.
But then the Jedi are all brainwashed slaves anyhow.