Feedbacks from any faculty/faculties(?) are welcomed.
(should this be in plural, and why?)
No, it's always singular. It's like 'advice'; it's a non-count noun.
Feedback (As a title, should it be plural or
nounsingular ? Why?)
It's always singular.
I would like to see the guidelines from previous years to be made available on the website.
(3) A negative feedback OR Negative feedbacks
'Some negative feedback.'
Is there a more comprehensive way of understanding when and which situation plurals may be applied.
For 'feedback'? It's always singular.
Student or Learner