I don't know if most players would agree with me but here goes nothing,
First of all, i feel like quest givers in Skyrim should be able to respawn (if possible, all of them) especially important quests like the quest for Volendrung. First thing i think about when i see a village of orcs not wanting me to let me in is, kill them all lol. You can probably guess that's exacly what i did and now i can't get the quest to lead me to Volendrung which is something i was really looking forward to getting although i only learned about it later on, after i killed all the orcs in that village. And by the time i learned about Volendrung, there was no way of going back to the save before killing all the orcs because i know for a fact i don't have that anymore
Second, I've seen a few people on the internet complaining about this, Aela The Huntress just doesn't leave me alone! she follows me everywhere because as most of you know, she is kind of considered a guard and pursues you everywhere you go if you have a bounty and happen to go near the companions building. Now don't get me wrong, the bounty is no problem to pay off however, it's still annoying considering i sometimes forget about some my bounties and she ends up following me again -.-
Last but not least, some might argue with this but i just feel like putting it out there, alot of quests and misc quests don't get marked on the map when you make them your active quest. I feel like everyone of them should be marked so you know at all times where to go. After all, Skyrim is a big world with many locations, it's easy to forget where some places or characters are.
Thank you