Can I steal anything without repercussions?

When I arrived in the first village, the tutorial popups warned me that I should be careful not to do anything that would draw the attention of the guards. I ignored this advice and went right to looting the houses in the village and taking anything that isn't nailed down.

This doesn't seem to have any effect so far, and no repercussions. Can I really just loot anything, or are there some things that will trigger a response if I loot them? Are there any indirect consequences of stealing everything in the game?

There are definitely repercussions.

I looted some things in the military camp near the first village, wanting to see if there were any repercussions (keeping in mind I did it in plain sight) and I promptly got my arse handed to me by the entire encampment.

They took some cash from my pockets and rather than reloading from last save, I 'woke up' in the encampment (sort've like how dying in GTA and other games works) and they weren't aggressive towards me any more.

Witcher 3 isn't like Skyrim where if you steal you are considered a Thief and get a bounty on your head.

EDIT: There have been some developments folks! I was just playing and if you try and loot at the Nilfgaardian Camp in White Orchard in front of the guards they will become aggressive and put you down. You wont die. What happens to you is described below. (NOTE: I'm playing in Blood & Broken Bones Difficulty)

About the warning, imagine you draw the sword and attack people, the guards will be aggressive towards you aswell and attack you. If you lose an animation plays out where they dump you and steal some orens from you (and you actually lose orens).

If you kill a goose for example a message appears that you're causing problems and the guards may be agressive towards you :D I mean I would be pissed too if someone killed my goose :D

It's a nice little touch from CDPR and that's why they warn you about that.