ad 1)
there are different ways of hiding pins: configuration pins like the Fullscreen Dimensions on Renderer (EX9) are hidden by design as they are not supposed to be possibly changed at runtime every frame. you create a configuration pin by using the Config attribute instead of the Input attribute, like so:
the alternative is a normal input pin with its Visibility attribute set to some other PinVisibility than its default true.
ad 2)
for a general tutorial read dynamic-plugins. creating a renderer via code…in theory kind of yes. in practice this is not a trivial task…what would be the reason for doing so?