ahh = [ I was wondering why I couldn't talk to you anymore.

For me personally, it just depends on how you read it in the sentence. Most of the time though, I would think that "no good" would be used more for past tense type. "Not good" seems like it would be used more for talking about things that could happen in the future. I'll give an example. The girl cracked her head open, and it was "no good". - It already happened, it happened in the past. If the girl falls, she is going to crack her head open, and that is "not good". - This will happen if the girl falls. (Future)

La morale par Orelsan

I would almost go as far as to say that "love" is the most important. Love for God, family, friends.....

Yes, most consider it vulgar. Instead you could say something like, " It makes me so mad, frustrated, irritated, annoyed. Words like that.