When you let go of a movement key, Geralt takes around 1-1.5m to stop. It took several goes for me to get through a door, I was too far to the left, so I held right. Just as he lined up jogging kicked in, I quickly let go and he was too far to the right now. So I moved left and overshot again. You have to keep tapping movement rather than hold if you want accuracy (but slow).
Have you ever played Operation Flashpoint? Great game, but the movement felt horrible, a bad combination of laggy and awkard. That's what Witcher 3 is reminding me of.
Hopefully this isn't spoiling things.
The first tiny village you find is burned down. There's peasants standing around crying. In my typical RPG mind I assumed that npcs+village+traumatic event means quests and dialog. But no. None of the peasants would talk to me. Only the children have a talk option, and they have two alternating lines each (boy says "What?" and "Grrrr", girl makes a noise or says "Don't touch me"). I entered a house, a woman was crying over a corpse while a boy stood nearby watching. I walked over her husband's corpse (with collision detection, so I actually bumped up over him) and looted a cupboard. No reaction. I bumped into her, she walked out of the house complaining about someone she knew being a whore, leaving me (a looter) inside with her son and dead husband. I guess grief makes people act strangely.

I walked to my horse (which won't come to me when I use the horse summoning whistle). People started screaming. I ran back. A guy screamed, then had a talk option icon over his head! Yes, quest time! I talked to him. He says something like "Good day" in a happy voice, then started crying and ignored me.
Now I'm at a real town, hopefully it will let me do something.
I'm also going to have to turn down the graphics settings, it dropped to 37 fps inside of a house when I used Witcher vision (mode to find interactive objects).