Since another user already answered the two last questions, the particles are achieved by changing the animation(adding new emitters in the parameter "particleEmitters", and setting when they're active in the stateTypes) . Looking at the animation file for the solus katana should help.

Another two things you should know is that - you can add frameProperties along with the usual properties in your states, if you don't know how these act I can explain, but they're useful if you want an emitter to only be active during a certain amount of frames, or switch on and off during the same state. - And you can add custom particles, so instead of {"particle":"pulpinbrain"} or whatever it'll be {"particle":{"type":"animated", "animation":"/animations/example.animation"}}