Don’t have an answer for your first question, but for question 2 Houdini is a popular one. I personally haven’t gotten a lot into sims but when I have I used Maya and FumeFX. Actually taking another look at that video you posted (wasn’t loading before) a lot of that stuff can be achieved within the shader/material (minus that ink effect at the end which is obviously a sim). I’m not a Unity user but there seems to be a lot of cool work being done using ShaderForge in Unity. @Sirhaian released a lot of cool work that he has done that might serve useful to study: Releasing my League VFXs Fan-Arts for Study Purposes - #21 by CellarPhantom
Didn’t really answer your questions but hope this helps 