It kind of helps if you have access to the quest chains, Sarko. Where did you get the magic order? Don't be telling us it is easy if you had a road map unless you can show it to us.
The complaint here wasn't that there are too many, too hard to do, it is that there is no way of knowing if you are even on the right track. Surely if there are going to be distinct paths to the same goal there should be some indication. Perhaps there could be a color coded symbol added to the quest dialog windows so that we do not have to waste time on quests that are irrelevant. Say you decided the symbol was an @, it could be white for guards, black for thieves and green for merchants. For common quests you could use different colors, grey for thief and guard, brown for thief and merchant, orange for merchant and guard and yellow for all three. This would only appear when the particular quest was on offer so that later ones in the chain would not be immediately known.
I suppose that would be too much to ask.