When Kanan and Ezra are sparring against each other, their light sabers are in training mode. The blades have dimmer shine and produce a different sound. They sting but do not cut or burn upon impact.
The Krykna spiders are based on Ralph McQuarrie' artwork in which they were creatures found in the swamps of Dagobah. In the Expanded Universe they were known as 'Knobby White Spiders'. The original design had 8 spider legs, but the Krykna only has six, because this was easier to animate.
Although Zeb refers to the little shelled creatures as 'Bogans', according to Starwars.com they are actually called 'Dokma'. The word 'Bogan' was the name given to the dark side of the Force in George Lucas earliest drafts of Star Wars. It's counterpart, 'Ashla', which referred to the light side, was mentioned by Zeb's people in "Legends of the Lasat".
In Australian slang, the word 'bogan', as said by Zeb, means something similar to 'redneck'.
Zeb refers to the small shelled creatures as bogans. As well as being the dark side of the force in George Lucas' original Star Wars screenplay bogan is also a derogatory nick name in Australia for someone uncouth or stupid, similar to redneck in the USA or Hoser in Canada.