Haha ,I just tell you.actually，These are the language habits of the Chinese people，in the meaning， The "幸苦"and"麻烦" is almost the same.As I've also difficult to distinguish between "anyhow" and "anyway" .Don't think too much, Which do you prefer and just do it , anyway language is always developing. 不要想的太复杂，其实都差不多。喜欢用哪个就用哪个 反正语言也是不断发展的。

Look up in the dictionary you will find that these words almost have nothing in common “辛苦” adj. hard, toilsome, exhausting, toilful v. work hard. “麻烦” adj. fash n. fash v. trouble, bother, put someone to trouble n. trouble, bother, burden, labour, labor, plague v. plague, burden, cumber but ,in our daily life, we have many kinds of expression to express our gratitude to others. Two of them are: 1）辛苦你（您）了。 2）麻烦你（您）了。 different from the simple word "xie xie" , when we ues 麻烦你（您）了。it means that a person help you a lot. in English you may say: I'm sorry to trouble you so much,and thanks for you doing this for me. 辛苦你（您）了。 in english you may say like this : Well done. That Was a hard job． Good work /Good job ,You’ve got a hard job． Thank you for your great effort. frankly,in our spoken language,we use 谢谢 more, especially to our close friends the sentences above are used to express gratitude to the people we just know or this person really help you a looooot.(but,you are not really close)

辛苦will cause hard work 麻烦 will cause troubles

麻烦: trouble (exactly the same) 辛苦: hard / work hard adj: 他有一份很辛苦的工作。 he has a very hard job. (this job needs him work very hard) adv: 他辛苦地工作着。 he works very hard.(his work maybe dont hard but he works very hard) in dictionary: 辛苦 means pungent;hard;toilsome. 辛苦 is normally used to express a feeling which people will get after hard work. the opposite word of 辛苦 is comfortable

I'm not Chinese, so maybe I'm wrong. But I think 辛苦 means real toil and physical suffering, but 麻烦 is like a hassle or annoyance.