Thank you for your concern, Alma,
It is true, the Thieves Guild are a risky bunch to get involved with. If you upset them they can see that you have an Oblivion of a time trying to buy anything and will raise prices on you or ban merchants from selling to you.
Of course, all this relies on a person being in an area that has a large thieves guild presence, mostly within the Rift, although they of course have influence over other areas of Skyrim as well. That said, there are plenty of merchants with whom one can find to involve one’s self with if absolutely necessary, it is just bothersome.
Beyond that, people would have to know that I am the same person who is coming after him. They need at least a name and or description to be able to seek their vengeance. I am not one to go into a situation without finding out what it is first. Before I do more than inquire about him, I am going to learn what I can about his exact relationship to the guild. If he is a prominent member, then I will proceed differently than if he is a fence or an informant.
More importantly, my actions would have to be traceable to his fate. If he is found with a hatchet buried in his skull in a back alley, there is little to tie me to such a crime. Surely a Nord would be a far more likely suspect. And I would not doubt that this Altmer, with his rude way of treating customers, has an endless list of potential enemies. With a tongue like that, it’s no wonder. Some lowly bard, who has been proven by upstanding citizens, guards, and members of the Companions, to be weak and incapable of hefting even the sword on his belt, is not going to seem a likely target.
I am more likely to be suspected of hiring someone to do something about it, but even then, I have those who would attest to my generous nature. No, it would be, particularly to the simple Nord deductive sciences, most reasonable to assume that I had been so piteous in my pathetic fancy man grief, that some drunk Nord decided to take pity on my woes and take care of the offending mer for me. Nords are not likely to have much pity for an Altmer, especially if these whispers of an upcoming war with the Dominion prove true.
But Alma, you are probably still worried after me. Yes, it is risky. Yet when has risk alone ever kept me from doing what I desire? I calculate the risks and in this case see that even should things eventually bring to light that I have some connection, I am unlikely to be considered a suspect and would only be considered so in passing. I would be off their list before tens of others in Whiterun, let alone the unknown many in the Rift or other places ,who he has treated so poorly. So long as I can get to him before he finds out about me, there is little danger of anything of consequence.
Thank you for your fears, but have a little faith in my skills.