To answer the "hag" storyline part (full game not EA): yes it is possible to get a permanent ability increase by +1 by finishing the hag quest. I did this in my current play-through. Some pretty big quest spoilers:
- Reveal that Ethel isn't just some adorable old lady but a villain.
- Find the secret passage in her home to have her reveal her true self.
- Find a way to go through the magic door in her lair.
- Beat up all the NPCs and then the hag herself in a classic "boss fight".
- Once beaten she'll plead for you to not kill her and if you spare her, the reward is to pick a stat of your choice which will get a +1 increase.
I'm pretty sure there are several ways this quest can be played out, with or without the various innocent NPCs getting killed in the process. Depending on your play style, you might want to take her up on the offer or not.
Also note that the fights are pretty tough so this isn't something you should be doing too early on in the "Act 1" map.