Some seem pretty obviouse. The miner for example we can assume it was her exhusband. The orc bard, I'd say the owner of the inn maybe hoping that being rid of him would get more customers(The girl in the tavern in Dawnstar should be careful if she ever comes to Morthal.) Can't imagine why somebody thinks the beggar in Ivarstead deserves to die. Same with Anoriath unless there was a PETA member living in Skyrim that I hadn't heard about. Helvard, I wouldn't be surprised if the former Jarl had something to do with that. The pirate captain, I'd guess the girl who sells Balmora Blue, she does complain about being overworked. Or maybe just one of their victems. Any other ideas as to who contacts the DB?
As i remember, the bard was due to Astrid having a lottery to determine the "winner"...since there so many requests, lol. Maybe the innkeeper got lucky, idk. As for the elf in Whiterun...idk. I always thought his brother wanted you to whack him out...but I could never figure out exactly why. Maybe there's a note somewhere that can shed some light on it. --- "I'd rather do black tar heroin with Alanis Morrisette than watch a quarter of Canadian Football" - Colin Cowherd