1- the FGC isn't to blame at all, has is defects like every community (especially online where pussies and bullied guys irl will trash talk or insult... or skill=power so famous people are treated different.. like in every environment), but if you want to get good simply pick your best pg in ranked and once you get to some top100/200 ps4 start adding strong people. Usually 1 out of 5/10 will result in a nice sparring partner. So in 1 hour a day you can make a new buddy every day.
2- No one cares what you did in mk1965 vietnam edition, in the little time pro players have they search a challenge, not students with past achievements, and you can easily become top world without playing sonicfox, theo & company (eu has proven that many times), if you get a game and impress them i guess they will be happy to play again tho
3- again, idk how u can blame the FGC. To get good you just require individual skill and knowledge, no ability of teamplay or to deal with new situations, no roles to learn or the skill to "be lucky enough to find a decent team" plus the playerbase is very very small. Try to play csgo or lol with millions players per day where u can get to insanely high skill levels after thousand hours spent and still never SEE (let alone play with them like buddies) at all a pro player playing
4- travelling in eu is very hard actually, the choice is between 10 hours in car or taking a flight, everything supported by a strong barrier language and then very high prices for tourist in everything. No one ever spend hundreds euros to get couple sets offline in eu, especially with the new netcode that works greatly.
5 dont get mad at some random imaginary online persona or take it personally, move on. If you know you are right in some matter (ie. the black adam vs black adam thing) move on, who cares what some online stranger says to you or if he doesn't treats you like your mom would. It's an harsh world. But also sometimes rethink about yourself and your actions too.
Hope you will rethink on how you approached the community, but if you move on with life even better, good luck