I don't think we are talking about the same quest...

But my point is that you shouldn't dodge starting the quest, you just don't have to finish it.

We are; The Molag Bal quest, and the guy DOES [censored] at you every time whether "you've seen anyone enter or leave the house".

My point is that I don't want to be stuck with unfinished quests; there should be different ways to solve it; my char should be able to lure the Vigilant away and slit his throat because I'm a vampire or go in there and defeat Molag Bal because I'm a knight. Similarly I should be able to decorate the streets of Riften with Brynjolf's guts if I so wished because maybe I'm a necromancer or something. Anyway you get the point right? More than one way to solve a quest and the option to fail quests is what we need.

I quote just this part to point out that those are not journal entries, they are quest objectives, which are not written in 1st person. You were not the one writing them down and neither did your knight character, so you shouldn't feel forced to do what it's written in the log. "Kill Grelod the Kind" is not a journal entry, it's more like a bookmark, Skyrim doesn't even have an ordinary journal. But I agree that the ability to hide unwanted objectives would be very welcomed.

making essential NPC's unkillable to environment but killable to the player would fix a bunch already.

Totally this.It annoys me to no end that i cant deny a quest,or if im forced into a situation like the Molag Bal quest,i want options.

I learned very quickly that, with this game, I was going to have to give up my OCD tendency to like a nice, clean, uncluttered journal if I wanted to stick to my roleplay. Sure, a way to outright refuse quests would be nice, and I really hope they include that in the next game, but I think it's too late to hope for that for this game. Hell, for this game, I just want them to fix the bugs and glitches rather than trying to do something new!

Quests are never forced on you. Yes, they will show up in you journal, but you don't have to do them. My current character, for example, has Thieves Guild, Dark Brotherhood, Boethia (or whoeve that Daedra is that makes you kill people) in her journal, but she'll never do then because she basically moral. She also did Mehruns Dagger, but refused to kill the guy so never got the weapon.
So while if would be nice if you refuse quests or remove them from your journal, you're always free to behave as you see appropriate for your character.

So: character gets hassled by guy. Goes into house. Has to kill guy, given no choice when guy goes mad. Gets asked to kill someone by evil demon-god. Won't do it ever, character is a good guy. Player gets annoyed by quest in UI, which character knows nothing about, what with being a virtual character. Player makes character do quest even though it's out-of-character-for-character. Player complains that character is dumb.
Yes, it is not good that there is so much 'do it or don't', and not so much 'do it this way, that way, or just kill them all'. That is a legitimate complaint. I don't think 'I could do it or not, and couldn't help choosing to do it when I had the choice not to' is quite so reasonable as a point to moan about.

hold on, lemmeh stop you right thar.

The character knows everything shown to the player mkay, including the quests. its why you have GPS pinpoint accuracy 3d map systems. the Character knows plenty, they are the medium/receptacle of which the player gleams information/quests (one of them)

end spoken stuff.

They know some guy asked them to do something. They may have written it down. They don't have a clue it's bugging the hell out of someone in the real world writ large in a font perhaps better suited for Halo than a Viking-esque fantasy game.