And for example, finding another species which will REALLY resemble humans with it's looks would be rather weird.
I don't know about that.
While part of me is pretty sure that we may have trouble recognizing alien life when we eventually do find it, another part of me wouldn't be at all surprised to run into something vaguely human in appearance, thanks to developmental biology.
Oddly enough, there is a stage in gestation where you're beyond ye-olde-ball-of-cells and into actual developmental features when it is nigh-impossible to tell a pig, an alligator, a chicken, a fish, and a human apart visually. All of these organisms pass through a couple stages, first where their gene expression is near-identical but their appearance is different, then there appearance is identical and their gene expression is different, then back to the first case, and finally both diverge. This is because, on Earth at least, there are certain physical features that absolutely must develop at a certain point in time for a viable animal to be produced, and this is - in part - why pretty much all vertebrates (even fish!) have the same basic features - 4 limbs, a head, and a tail. I would not be at all surprised if we ever find planets that could support human life that the life that developed on them is physically very superficially similar to life on Earth because of this. Mutations are random, but selection pressures and successful strategies to overcome them are not.
While Star Trek is often guilty of annoying me with things like "oooh nose ridges," the concept that alien life may look a great deal like life as we know it if it develops under similar planetary conditions really doesn't. Throw in a different set of planetary conditions, though, and all bets are off.