How useful or necessary is it to learn CPP in order to really master effects in UE4?
8 years C# experience but find CPP a bit of a hurdle.
Can I stick to Blueprints?
You only need to use CPP if you find yourself stuck due some stuff that is not currently exposed in Blueprints (which you can usually quick fix by just exposing it yourself, which is easy to learn).
Personally I couldn’t adapt myself to Blueprints due my years of previous C# experience, and CPP in UE4 feels pretty similar to C# to me (even more if you are familiar with Unity like me).
So stick to what feels better to you, and learn the other when you find any special needs.
No. A lot of people are building visual programming tools, but they won’t make any difference. Most people are writing spaghetti code, and you can also create a spiderweb in a flow chart GUI. You need good design and code quality, whether you are typing code or clicking on a GUI. Plus, clicking on a GUI will always be slower than typing code.