I learn Japanese from many sources including movie or anime. unfortunately Japanese often pronounce it different from actual word that make me often failed to find the translation, for example すごい becomes すげえー, でかい becomes でけえー, たかい becomes てけえー. so my questions are:
How does this work? Is it that simple just replacing おい、あい to えー？because I think never hear someone saying kawee for かわいい。
Are there any Japanese male versions other than replacing あい、おい to えー OR な vs ね?
There are no hard and fast rules, but 'a' and 'o' sounds in い-adjectives are often turned into glottal stops, like たかっ、せまっ、はやっ、すごっ、おそっ、etc. Among them, some 'a' sounds are also changed to 'e' sounds, like the すげー in your example, or きたねえ etc.
On the other hand, 'u' sounds are sometimes changed to 'i' sounds. For example, わるいー＞わりー、さむいー＞さみー. Apparently, this can sound a bit girly or childish, but that's open to interpretation. Again, this doesn't apply to all 'u' sounds. You could use さむっ！ to emphasize the cold too, for example.
In any given language, there are always words (usually very commonly used words) which adopt unique characteristics that cannot be applied to other words in the same linguistic category. Unfortunately, it's just one of those things you have to learn through experience and use. There may well be phonetic constraints on which words can be changed, but I'm not aware of any linguistics papers which have focused on this kind of phonotactic conversion.
I think most Japanese people don’t know why すごい becomes すげえ or でかい becomes でけえ, because it's highly specialized knowledge. I don’t know either.
If you really want to know the system, I recommend you a book on Japanese phonetics. Like this.
But... I think it’s not necessary to learn and speak the Japanese language. I think it’s similar to the situation when you’re asked why ‘I want to’ become ‘I wanna’, isn’t it?
たかい becomes てけえー-- 「 てけえー」ではなく「 たけえー」になるのでは・・other than replacing あい、おい to えー...-- japanese.stackexchange.com/a/18458/9831