I have to tell you, that I started this game on release day, and on my first character had 90% of the quest content completed other than two factions. All this before the second patch. There was a release day patch. Anyway none of my quests failed or broke. I had two issue where i had to load an earlier save because the game glitched and the quest would not work, and no these were not the ones that most people talk about.
It is not a guarantee that the game will glitch, it is just something you have to prepare for. That means not playing on one save, not using the autosave features and always having a save to go back to from before you got the quest in question.
Also, try not to start, accepting is OK, but starting too many quests at once can lead to indigestion of the game.