I don't really have the same problems Cero does with expectations and such. I mean, I do have expectations for games, it's pretty much impossible not to, especially in a long-standing franchise and one I have personal attachment to (I'm still speaking in general here, but this does happen to apply to Fire Emblem), but I'm pretty much ok with enjoying a game just because of it being hype or shiny or new. Like, if i find something fun, even if it's actually bad, it's whatever: I mean, I'm having fun, so is it really worth complaining? Does analyzing things and only enjoying that which is truly well-done give me some sense of accomplishment, make me feel intelligent, etc.? Not really.
So I don't regret enjoying Awakening and I'm not going to say I was wrong to enjoy it, either. Am I aware of its flaws? Sure. But if I'm going to be that way I'd almost never enjoy anything and I could point out flaws for pretty much any FE game too, if I cared, but I don't see what's the point in hurting and depressing myself and possibly others. If it's not something I notice to start with, if it doesn't actively bother me, then I don't see why I should go out of my way to try to make it bother me. If my instinct is "I don't like this", then that's one thing, but I like the expression "ignorance is bliss" because it goes both ways; it really IS easier to enjoy life when you're not hung up on the details or even if you just don't know them (for me it's usually the former though), but at the same time not knowing them is kind of beneficial and you can gain a better appreciation for things... it's hard to find a balance but what I do is, I just try to enjoy the good parts of anything and if the bad parts are tolerable, I tolerate them. And of course, is something actually meets a higher standard of quality to me, then I'll treat it a little bit better.
I think Fates was an exception to this because I let myself be taken in by IS's sweet words and really wanted to hope and believe, especially after the personal disappointment that was Zestiria (though that was about letting my expectations become too much and more of "I just didn't like a lot of things about the game"). So yeah, I got carried away a bit and this is pretty much the most mixed feelings about a game I've ever had, at least as far as I can remember.
Anyway, to the point of the topic: I generally either totally hate spoilers or don't mind them. If I have enough interest in a topic/subject such as a game or show that I plan to experience it for myself, I do NOT freaking want any spoilers on it. Heck, even people telling me "it was so good" or giving their impressions can create bias, especially depending on how they say it/how they come off. Some people are like "I found it really good, but you might not" which makes me say "ok, it might be good, but it's probably not perfect so clearly I should keep my expectations in check" vs. "this is freaking amazing you have to play it" and it's like "oh really? this better live up to your words or I'm going to be severely disappointed" lol.
That being said if I think something just sucks or I'm never going to actually get invested into it, then I don't care if you ruin it for me, because I don't really feel I have anything to lose. But most of the time, I am super sensitive to spoilers. Sometimes they can't be avoided because people are careless and/or insensitive and I bump into them on the internet, and other times it's just sort of how things go/the natural flow of things. For instance, I knew the Smash Bros. roster before it came out because I'd have to hide from the internet to not know, and I saw most of the official footage of Xenoblade X because I figured, Nintendo probably wouldn't show me things that are going to ruin my experience of the game... and well, I DO need to know enough about a game to know I want it and be hyped for it. But you could say "you wouldn't have known the details if you hadn't watched!" and you're right, so sometimes I do just have to draw an arbitrary line as to what's ok and what's not. Story spoilers are the most sensitive, but even gameplay features and the such can spoil things for me as they essentially inform me of what's coming up in the experience, and therefore don't allow to me to soak it in for myself from the start. XP
Finally, as far as waiting goes, it really depends on the game. Some games I don't think will ever come over, or not anytime soon, and in that case I may import it near launch and just avoid launch spoilers (usually not too hard if it's an import) and experience it for myself. Cool stuff. But take Fire Emblem, with how the community is and me being an FE fan, it's pretty much impossible to stay away from all levels of spoilers without avoiding the internet/having someone else take over my job. And it stinks but due to people being insensitive, I had quite a bit of the game ruined for me or had impressions of it imposed on me, if that makes sense; like "this sucks" or "this isn't good" or stuff that makes me think harder than I might otherwise, or analyze more than I might otherwise. Instead of just letting me play the game naturally, for better or worse.
For games that have more than just a couple days between the English and Japanese launch (most games), I just wait like a normal person and don't spoil myself. I do this for most games and I'm almost always fine with it. Even games where I'm impatient and I want to know what happens, I can wait. I mean, I did properly wait for most FE games, including Awakening, so... :\
For games that are launched in Engilsh first, spoilers isn't really an issue because I can experience the game for myself and just avoid contact. Again, I think FE and the such is the exception because I don't have to look far to see people discussing it. For games that I don't get at launch, I'm probably not invested into the series enough to A) be tempted to look into spoilers or 
to accidentally stumble upon them, so in that manner, I don't usually need to put any extra effort into avoiding spoilers, it just kind of handles itself.
So I guess to zoom in on the real focus of this post...
tl;dr I try to avoid spoilers as much as I can, while still doing my job and interacting with other FE fans. In the case of Fates, I'm playing it myself, so I can "curb" what little temptation there is to know what happens by just continuing to play, but even so it takes a while to make progress, and I don't import most games before they come over in English, so I get the sentiment and I usually just deal with it while secretly being jealous of people who can get the game before me and actually understand it, lol.
EDIT: I realize it's weird what with me having the game before most people because I have a Jap 3DS and all... still, it's not like I don't have a life and can beat the game before spoilers come out, so I've been just as susceptible as anyone else, really and will be until I've actually experienced enough of the game myself that I don't have to be too concerned about specific details being spoiled. There's still the dumb 3rd route though
