-No
-Amazing Visuals
-Positively: in moderation. A CGI spectacle like Avatar or 2012 is nice to look at, but leaves me feeling totally unfulfilled. If visual effects are used to compliment the story instead of having a "wow" feature in every shot, then it's being used cleverly and effectively.

(I have no idea what I'm talking about.)

-No
-Amazing Visuals
-Positivelyish: Same as Smeagol, it greatly depends on the film.

-No, but think it does help in some cases (are you talking about commercial success or critical success?)
-Amazing visuals
-Positively (same reason as Smeagol and 1011ev)

-No
-Amazing Visuals
-Positively, if done right, that is.  The effects have to fit the visual style/quality of the film.  If the effect fits, then it looks convincing.  Such as;
Realistic live-action = Most realistic effects as possible
Cheezy live-action = Can get away with a little less realism
3-D computer animation = Depends on how realistic the appearance is, usually less realistic
Stop-motion = Less realistic, somewhat cartoony
All 2-D animation = Least realistic, cartoony

I noticed that in brickfilms, many people make the effects too cartoony (like it was meant for a 2-D animation, just about any effects done in Paint) or too realistic.  But the effects AnnoyingNoisesProductions uses are very fitting to Lego.