It's pretty much impossible to become fluent in a language if you don't get to speak it in anykind of natural environment, you basically have to move abroad or be forced to speak the language at work/school/have native friends. Every Finn has to study Swedish for 3 years, most for 6, (we've got a Swedish speaking minority so it's an official language) but most can't speak it to any practical extent because A) everybody hates it a school by principle B) you don't hear it outside the classroom ever. I've also studied German for five years aged 11-16 and can barely say hi/thanks/my-name-is. I've got a feeling it would come back to me very quickly if I started using it now though and I might really learn it because I'm way more motivated now. And it probably made learning Swedish a lot easier for me.
I'm a bit surprised that almost every country (excluding some states in the US?) seem to have mandatory languages in high school/secondary school. Like said a couple of years a lessons probably doesn't teach much useful stuff but I would suppose just studying a foreign language should be good to help realize that not everybody speaks your language, what's it like to communicate in another language, what kind of differences ther are etc. To realize the whole plurality of the thing, even if you don't learn to actually speak any language. I don't blame anyone for not learning another language besides English when it really is, and increasingly so, a pretty universal lingua franca. That just shouldn't be taken for granted.
It's actually really really helpful to get to hear the language in your normal life even just for a little bit. My aunt's husband is Swedish and although I speak English with him I get to hear him speak Swedish with my other relatives from time to time and just being around and hearing that, not necessarily even trying to listen, has helped with my Swedish a lot. I can't speak much of it, but the little I know comes pretty naturally to me. It's the difference Dada talked about in the other thread between learning and memorizing.
People have all sorts of languages in Auckland, and although English is the most commonly spoken, I don't think people who have English as their first language are a majority group. I don't understand most of the conversations I hear on a daily basis and I don't think anybody else does either. Sometimes when speaking I translate what I want to say into a simpler version if the person I'm talking to is clearly having trouble understanding me (hopefully not in a patronising way!) I end up speaking the same kind of intermediate English that two people who share it as a second language speak, but with more fluid pronunciation, intonation and syntax. The way that that kind of tips the power relationship in conversations in my direction in conversations makes me feel uncomfortable.
I always feel somewhat embarrassed when I talk English to a native. It's really stupid but I can't seem to get over it. Kinda sets the whole power balance of the situation like you said, feels like I'm always talking to my superior, especially when I realize my ideas sound a lot dumber when I explain them clumsily.
Language barriers can feel quite alienating. Especially when everyone around you feels alienated in the same way by you. Sometimes people use a shared native tongue to have encrypted conversations while people who speak only English are stuck in cleartext. As cities become increasingly multicultural and multilingual, I think that it's going to be more and more necessary for people to speak more than one language. From what I've read, second language speakers typically don't gain as much proficiency as native speakers ever. Their speech typically remains laborious throughout life. Taking this into account along with the huge number of possible languages, it seems like a lot needs to be done to enable as many people as possible to be able to communicate with one another on common ground. I'm not really sure what's being done about it. It seems to me that people should at least be able to speak a few different languages, and that's genuinely pretty hard.
Yeah, you can never learn to speak like a native. I find that somewhat scary. I'm think about about moving abroad, most probably an English speaking country, in a few years, and although I'm absolutely confident I can get along fine, make friends do my studies and in that way integrate, it's a scary thought that I'll never be able to speak Finnish there to anyone. I don't know how fluent I'll become with English, but I'm afraid that even with the people that become really close to me there I'll never be able to freely express myself, just let things flow out of my mouth. Maybe it won't be problem, but it sounds like it may be very alienating from the whole society and very stressful.