A queen is 9 points But she can get captured by a pawn, I think a knight would be worth around 11 points.(P.S. i don't know anything about the .25 of stuff like that so this is just my thinking)
Knight that is immune to pawn capture: what is its value?

How strong the knight is and how much this would affect them is also dependant on board size.
It's also dependant on e.g. how far forward the pawn can go initally. e.g. in a 10x10 board can the pawns initially move 2 squares forward or 3? That's going to affect what role the pawns play and therefore how powerful the new knight is. (It will also affect how powerful the pawns are, which is how "+0.75" is defined).
It is generally known that bishops get stronger as boards get larger, for instance in Capablanca 10x8.
I'm interested in ways to empower the knight without major adjustment to the piece, to maintain near-parity with the bishop or at least some other piece of sufficiently different flavour.
Would it be worth +0.25 pawns over a conventional knight? +0.75 pawns?
Then how about for a rook?