Haha nice; you should absolutely visit!! Are you a good singer??
Well yea, in my personal experience, I didnt have any integration problem whatsoever so big yes to the first question! But I am generally good at adapting and always trying to behave as much as I can as locals, so that probably played a lot (am not like the typical arrogant french tourists I see everywhere......)
About the language itself, it's a bit hard to give an accurate period... I can handle most situations on my own but I wouldn't consider myself fluent yet (especially writing) coz unfortunately I never had the chance to properly learn it. I wish I could just take classes in a language school, with a teacher, without thinking about anything else...! But I studied it while working with books and topik practice tests, and using it in the office, also watched a lot of tv programs without subtitles... Never fully understand 100% (still hard to grasp all the nuances and stuff), I am much more comfortable with written contents lol, reading is quite easy!