yes it is completely normal to have a fight and a rough patch in relationship these days.....what matters is that even after a fight u don't want to leave that person!
yes, absolutely fights are important if you are in a perfect relationship, but the fight should not be often !!! and if you fight often it's so immature relationship!! just tell him/her about your expectations from the relationship. so that he/she knows about your issues exactly and if your significant loves you they will try not to do those things which makes you uncomfortable!!. conversation & understanding is the key to a healthy relationship! TRY TO UNDERSTAND YOUR PARTNERS NEEDS & SITUATIONS TOO.
yes omg it's completely normal to have fights. but ensure that you both sleep in the same bed even after all fights. perfect relationship is only made. no relationship is already perfect.. only if both of you want to move ahead of your fights then you will eventually have a perfect relationship. fights are a part of life