You get acne because you don't wash your face
Acne is caused by clogged pores, sebum, bacteria and inflammation. Washing your face will help reduce acne but it isn't the main reason.
There is no such thing as over-exfoliating
Over-exfoliation can cause irritation to your skin. Exfoliate only once or twice a week.
Washing your face with hot water is good
Wash your face with lukewarm water, don't spend too much time in the shower. This could lead to removal of oils and natural moisturizers from the skin, that will result in dry & dehydrated skin.
Men don't need moisturizers
Moisturizers are a basic step for skincare routine, regardless of the gender. Though men's skin is thicker and is oiler as compared to women, they still require a hydrating product.
Hot water opens pores
No, wash your face with lukewarm water. Pores aren't doors, they don't open and close.
A pea sized amount of product is enough for my skin.
Unless a product asks to use a pea-size amount, you must use as much as required to get all the benefits. It is not a one-size-fits-all situation with skincare products. eg: treatment products have a higher % of actives.