The salamander may be a reference to a creature known as a kappa. A kappa is from Japanese folklore and is attributed to negative things such as mischievous pranks all the way to drownings and rapings. It is said that the believe in it may stem from the Japanese giant salamander. It being black is a coloring choice by kubo to illustrate a parallel. This may seem like conjecture but... A hair covered kappa is known as a hyosube. That's right, just like ichibei hyosube.
As far as SS being evil well many times it has been stated that neither side in this war was right. The shinigami exterminated the Quincy and that can't have been a good action right? Not only that but the shinigami in SS arc were shown to be cruel. There are definite goo guys in SS but many are in fact bad. Remember the guy ishida fought in SS arc who was gonna kill orihime no problem.
Btw urahara is a bad person. He has used ichigo many times and has left out critical info on purpose. He knew about the shinigami combat passes true purpose and didn't tell ichigo. And now ichigo is being sent to RR when solely to delay the Quincy. Remember the visored girl statement to urahara in the recent chapter. Urahara was also doing hollow experiments which had very questionable morals. His quote to ichigo about benih r not being nice also tells his personality. He also was legitimately going to kill ichigo, his intentions are good but he is willing to sacrifice good people and doesn't even blink.
Forgive my lack of knowledge about Japanese legend and folklore, but what is the parallel between the salamander and a Kappa? Is it because the salamander was in a stream? If so then your explanation is plausible.........even if I think it's a bit of a stretch.
I agree with you about the quincy and shiningami being evil, but don't you think that what the SS did was a necessary evil? If I recall correctly, the SS attempted repeatedly to have open dialogue with the Quincy and negotiate some form of agreement but the Quincy outright rejected them. What they were doing threatened the balance between worlds and could have very well led to the destruction of both worlds. What the SS did was wrong from a moral viewpoint but also justified from a logical and unbiased view.
That being said, one can understand the Quincy thirst for revenge.
Kisuke Urahara? Yep, I agree that is one shady SOB.