is there a difference?

first of all, i do not suggest washing ur hair every day!!! u should take a shower, but dont get your hair wet(unless it gets really greasy)...you should usually wash it with hot water, but about once a week, you should wash it under cold water to add shine...if you do it any longer than that, then your hair will be like a mirror(shiny)

No difference except the hot water may give you heat rash!

it doesn't really matter as long as the water isn't too hot, just before you turn the water off give your hair a good blast of cold water. it will make it smoother and shinier, im a first year hairdresser. temperature is nothing while washing it's the ingredients in the products you use that count.

cold water is always better hat water opens the pores cold closes so hot water to wash cold to rinse

Warm water.