He solicits answers from some of the others who have come to lurk near them in the planning room for some of this.
The lords' protections generally include a number of Firebending guards, fortified manor compounds, personal combat skill (there is a dueling tradition called Agni Kai), and usually ability to call on the military proper for protection. Their best plan without her involved identifying one going on a sea trip at night, and having Lenora drive a large canoe right up under the ship close enough to board the vessel with an armed team. Or a straight up ambush of a carriage or similar, if they travel by land. The boat plan is probably not viable; Earthbenders (the best fighters besides Lenora) are as disadvantaged by the ocean as Waterbenders are advantaged. It probably fails when the Earthbenders and mundane fighters fall to professional Firebending killers, and Lenora is overwhelmed by them once she has no support. A night assault on a noble's home might work, they don't tend to recognize specific Earth Kingdom people/commoners and you could get close to the walls before being spotted and challenged by a guard if you manage to get into the town at all. This probably fails when the alarm sends reinforcements to the manor before they overwhelm the lord. Their servants tend to be Fire Nation natives, mostly, or at least Fire Nation commoners in charge of Earth Kingdom commoners.
In charge of Rojonu Town is Count Han of the Steady Bluetorch family. They are out of favor in the Fire Lord's court. He is cruel but largely uninterested in day to day affairs, his daughter and head servants run the place mostly by stamping down hard on anything that looks like resistance, resentment, or 'not knowing one's place'. There are also a number of Barons and lesser Lords, a rank that is still above 'commoner' but doesn't imply holding any land. Wulong and Chima Valley have no noble lord and are under military authority; They have a few names of officers, and rumors that another resistance group is active near Chima Valley. The Yu Dao region, on the far side of these mountains, is under a coalition of Baronial families known as the Five Flames Alliance. They are actively running people out of their homes, enslaving them, and destroying the environment with extractive industries, trying to make as much money for themselves as possible. There is a rumor that Princess Azula, the Fire Lord's favored daughter, might pass through this region on her hunt to capture or kill the Avatar.