Not to start any issues, but be hournest most of oblivions quest was not even that hard, when a compass arrow showd you where the cave was, and even worse, where the character you need to find is at thats not even possible.
In Morrowind, it could actually require some time to find the entrance to the cave, and thats actually what made it a fun.
Seriously, if the quests rely only on fast travel, its like playing the quests like your playing a linar game with "stages".
Morrowind was annoying because of the long distances to travel, the ammount of time to find a quest-NPC and the travel system via boat/silt strider/mages guild or almsivi/divine intervention being vague.. Oblivion beats Morrowind in that. I want to play a game, not to be searching for 30 minutes some place South-East of Ald-Ruhn and find out i was searching too far away from the city or look at every NPC to finally find out the NPC was right outside the mages guild in the foreign quarter. I realise it is more realistic, but it takes out the playing speed (and fun). In Oblivion i could fast-travel if i had little time to play the game. When i had more time, i liked to go walking, -you- have the choice, but don't leave out a fast travel. I have work, other hobbies and i am studying so i have little spare-time, for me it is a nessecity.
Daggerfall beats Oblivion qua fast travel. You had to pay for it if you would travel in "safe mode" via taverns and inns and only during daylight. Fast-travel in "Fast-mode" would mean you would travel all the time, no stops and a chance to run into enemies. (If i remember correctly)
Maybe it is an idea to leave out the quest-arrow for some quests. E.g. you've found the cave with the arrow, but you have to comb through it to find the "Gloves of the Imperial" or something like that.