I personally like Oblivion but I definitely agree with you that it is in the non-linear extreme. I think there has to be a few linear and non-linear extremes to satisfy certain players, but for most players a good moderation between the two is required. I agree with you that Dragon Age hit the nail on the head, my problems with the game were unrelated to this issue. It was simply holding my interest that was the problem, nothing more.
----Oblivion Rant----
However, I don't understand your quest issue with Oblivion. In most Elder Scrolls games, quests can be put off and in many cases have to be until you are more suited to accomplish them. However, being more combat oriented over stealth is even more trivial in Oblivion than all of it's predecessors, as picking locks and sneaking isn't quite as limited as it was in previous games. You can pick any lock at any time no matter your security skill, whereas in Morrowind, many locks had to wait until you had the proper pick, the proper skill level, or the proper spell and the ability in which to cast it.
There is a quest most people find early on, which is finding out where a suspicious shopkeeper is getting his merchandise and how he is selling it for so cheap. You're supposed to follow him and find out where he goes and then witness a meeting between him and another individual. If this is the quest you're referring to, it doesn't require stealth whatsoever. You don't even have to sneak to follow him, just keep your distance. When the meeting take place, you actually have to run up to them where you're in plain sight for them to commence, and they act like you're not even there. lol.
Regardless, I understand what you mean about it's non-linearity, but in regards to class limitations, it is just as non-linear. All major skills do is level you up and increase a little faster than the rest. I usually make a custom class, I always favor luck, because it's the hardest to increase. As a second choice, endurance is good because it determines health gained when leveling, so higher earlier is better, but strength means more loot to carry, etc. I also ignore my favorite skills and pick the hardest ones to level. That allows me to build up higher multipliers before leveling, as I favor non-major skills and the major skills increase slower due to being naturally harder to increase, and less used by me. For instance, although I use armorer frequently, it is harder to increase because you need damaged equipment in order to do so. Because of that, I almost always have armorer as a major skill.
