Can someone help me?

Well, im studying Mechanical Engineering (2nd year) in Greece (so non target ofc) but i found out that Engineering is not for me. Fluid dynamics, thermodynamics etc are really boring. I want something more challenging. So, i would like to become a trader. Some relatives do forex trading (mainly for fun) and i really like the whole concept so i want to be a professional trader or work where trades are happening (=HF). I consider doing a Master in Finance or a Master in Financial Engineering when i finish MechEng. I like researching companies and industries too!

1. Which country would you suggest me to do my master and why? Should i look at the more promising North America (USA, Canada), but face those visa problems (i will have a STEM degree though) or EU (UK, France, Germany, Netherlands, Switzerland), which is closer to me and has less/non-existent visa problems? I can speak english and french, but im working on it...
2. Can someone work at the buy side, without sell side experience? I find IB really boring but i know it opens many doors...
3. PE, HF, or AM? Which will be the best the following years and why? Whats the career progression that someone has to follow to be at any of those places? For PE i think it is quite clear: M&A>PE. What about the other two?

Thank you in advance!!! Ignore any mistakes :)