Note: I’m learning/teaching myself to be a Real-time VFX artist. I have yet to be in industry/salary and all that. Because of this, I have to skip your “Common” questions, as I don’t know the answer to them. So with this noted.
This one is the easiest. Realtime VFX vs Offline VFX. In movies, they are just frames that get rendered out then rotoscoped into the scene. Movie VFX can do basically anything they want or can dream up, with as many particles as they want, with as much lighting and realism as they want; because it’s a video. It’s just a bunch of pictures. Once it’s done, it’s done. For the most part, all they need to worry about is not screwing up the render farm.
Realtime VFX - AKA Videogame VFX, needs to render RIGHT NOW @ 30 or 60 or even 90+ if in VR, frames a second. It has to do this with not just one effect but with all the OTHER effects, plus lighting, environment, AI… so on. It’s not just about the effect, but how efficiently it is made to minus the expense on the CPU/GPU.
It’s a fairly artsy fartsy techy ticky wibble wobbley…uh… profession.
The benefits? They can render out some really nice particle simulations for VFX trickery, at minimum. What’s the benefit to a Swiss Army Knife? It helps get the job done in a tireless number of ways. Having more options to assist in the problem solving process is a nice thing.
Honestly, this is very likely to be something you are going to need to search on your own. It’s just too big.
I’ve only used Unreal & Unity, but I think I can answer this, so here I go. There is no best way. There is no magic method ( that I know of ). It’s all about how good of a problem solver you are, and how well do you know your tools. How well can you change your thinking? How good of a team player are you?
It’s all about the engine you got to work with. Are you racing with a Proprietary Super Car, or a Ford Pinto. At minimum there are some global things that are used industry wide, more or less - no promises, so I suppose that would be a good starting point. Then after that you just go “Who made this UI”! A programmer! Then you get over it while you have to, and do what you got to do.