I think that would be a shame personally, I think its quite interesting to have internal operations.
if its was just for constants, id argue that you dont need it... instead use 'reaktors' model, which has an easy 'one click' method (a bit like a comment) to add a constant to an inlet. (this has the advantage of better documenting a patch)
Is that necessary?
the current behaviour, which is the inlet is 'normalled to zero' is also arguably arbitrary, similar when you connect something that is also a parameter, its only by convention 'summed' - personally, I think it should just be part of the documented behaviour.
as you suggest in the second part, I don't think you can in many circumstances visually show a normalled behaviour.
I understand the desire for it to be visual... but Im not sure it gains much.
at the end of the day, I think its down to the 'object designer' to make sure normalled inlets make sense.
(arguably thats kind of the true of objects generally e.g. param/inlet name)
EDIT: actually the last point, I think is the crux
there are different ways modules can be created, different design philosophies , e.g. normalising to an internal clock, or providing a clock input
BUT the crux is... I dont think axoloti should 'force one approach or another' (for user objects, factory objects being consistent is a different discussion :)) ... I think we should allow the designer flexibility, and users and determine what they like