I've gathered a bit from the related questions I got, but I'm not quite 100% on what separates だめ,いけない and ならない each other, not to mention the differences between しなくちゃ、しなきゃ、しないと before the three verbs. Anyone know?
English is different from Japanese primarily in two aspects:
Order of words and articles in a sentence (so much that articles come after words, not before, and are therefore post-articles or "particles")
Levels of politeness/formality, or maybe even better said as "etiquette"
So imagine this: your society and culture are all based on rings/circles of people. You have your in-group, your tepid group (members of whom are in your periphery and might become a part of your in-group), and your "out group."
Another aspect is you have your friends with whom you speak casually and without etiquette, your peripheral people whom you don't know so well and use normal/polite language, and your teachers, senpai, higher-ups, with whom you use very polite and distanced language.
Fundamentally, all use the same words but they are formed into different shapes. Typically, the longer a construction is, the more perceived "etiquette" there is behind it.
If you had to rank them on their relative levels of etiquette and ingroup-periphery-outgroup'iness, what would you come up with, based on what you know so far?