You could bash your way through all the quests but it's the same as Oblivion, some quests reward you for doing a better job.
Alot of quests take place within holds so if you can't sneak or pick locks it's going to be alot harder. Also there are alot of enemies per given quest it might be challenging. For instance one quest you have to sabotage a mansion, it has like 30 boss level bodygaurds with alot of health.
I find stealth to be one of the best skills, sneaking up behind someone and 6x damage is magnificent, 15x damage with daggers, or slipping poison into peoples pockets and killing them right in the middle of a square without getting caught.
I did a quest that was glitchy as hell, if you use a dragon shout in dragon reach sometime after a courier will give you a letter pinpointing you to a dungeon called amberdean or something, your supposed to find a treasure only a dragonborn can unlock, I'm guessing it's a dragonshout. I was attacked by a summoned storm atronach and he got me with an ice spike in my arm, it never dissappears though I think it's stuck forever. You have to pull two levers to open a door, it glitched and the door won't open no matter what I do. The whole thing really ****ed me off..