Well, I haven't had problems with the save glitch so far, albeit I have heard many people complaining about it. Nonetheless, the Troll did give me some trouble, but it was not impossible to kill it. I used a warrior, probably died like thrice to get it killed, but as long as you bring a few potions and jump/roll to dodge his VERY slow attacks, you'll do just fine. Really, just hit twice, wait for him to begin swinging his club and jump backwards or sideways, shouldn't be much of a problem with the DK Jump. If you believe that you aren't ready, go back, hunt down some goblins and look for some quests that you possibly missed.

Level scaling is a little lame, makes the game way too easy, I believe. Oblivion is a fine game, though it is far from the perfect game that you mentioned, and it is not quite the same thing as Divinity 2. I believe this game is good as it is, it just needs some patching to deal with a few glitches. And this game is not all about going there and clicking on your enemies until they're dead, sometimes you have to be quick, jump, dodge, use some sort of strategy. Unless the level difference between you and your enemy is absurd, there is always a way to win the fight, or you could just avoid it to come back later when you believe that you are ready for it.