I do not agree about French being the most beautiful language in the world. As far as I'm concerned, the most beautiful language is a myth because each language is unique and has its own beauty, just like us, the human being. And for your second question, just as everyone has his strong point and weak point, each language has something simple and something difficult in it. I can't say that French is one of the hardest languages in the world since I do not know all the languages in the world (I think nobody does, the very multilingual that I know speaks 20 languages). I can only say that French is more complicated than English.
Concerning my French learning, I recognize that it was not easy for me when I started to learn it. There are many reasons for that: firstly, compared with Chinese, the French falls within a totally different language system. Its grammar is just like something of mathematic (well, German is worse... ), the conjugation does not exist in Chinese, etc. However, it becomes easier once it becomes familiar to you, and in fact this is something for all language learning. And just like French, other languages have something difficult for their learners too, for instance the Chinese or Arabic character...
Thank you!