1) Let us say you are planning to play tennis with a friend today but it is raining. Could you say to your friend: "Let's make it another day, shall we?" Does it sound odd? "Make it another day"?
No, not odd at all. Perfectly acceptable, common usage for many English speakers.
2) In the same situation, let us say you are about to leave home to play tennis and it starts raining. Does it sound odd to say "That's bullshit" or "That's so lame"?
I'd never use either of these expressions in this situation but some people would. Both would be totally understandable to me in context, as they would to many native speakers.
3) Does it sound odd to say "I need to put something in(ON) my window that blocks out the sun. My room gets too much sun/sunlight."
Does it sound odd?
"On" does not sound odd here. (Some people might use "in the window", too, when referring to the window frame/window area.)