Buddhism and thought crime Having read multiple sources about karma, there appear to be different interpretations. Some suggest that physical volitional acts bear the seeds of karma while others such as this one, suggest that karma is borne by thoughts. 

This is extremely confusing especially for someone new to the concepts since there doesn't appear to be an authoritative answer or reply. 

If there are "unwholesome" (since i don't know what are wholesome or unwholesome aside from causing direct harm with no ill intentions) thoughts, is this considered thought crime in Buddhism?
It is the intention that has the karmic effect in this life or future ones. This is made clear in the Abhidhamma, and by the Buddha 

There are three unwholesome roots. Which three?


Greed 
Hatred 
Delusion 


There are three wholesome roots. Which three?


Non greed 
Non hatred
Non delusion


For example: 
A blind monk, without intentions of any of the six intentions listed above, killed a bug when he was walking. And he was a thera. The fellow monks noted he squashed a bug, and were displeased with it because it is against the first precept to kill and to harm another living being. That is one of the ten unwholesome actions:


  "Here someone is a killer of living beings: he is murderous, bloody-handed, given to blows and violence, and merciless to all living beings." -The Buddha (Saleyyaka Sutta)


Later the Buddha became aware of what has happened. He told the monks that Cakkhupala's actions of squashing the bug will bear no karmic potency since he had no intention to kill it. 

Here is an excerpt of the story:


  "One day, Venerable Cakkhupala who was blind came to pay homage to the Buddha at the Jetavana monastery. While he was pacing up and down in meditation, he accidentally stepped on some insects. In the morning, some bhikkhus visiting him found the dead insects. They thought ill of him and reported the matter to the Buddha. When questioned by the Buddha whether they had seen Cakkhupala killing the insects, they answered in the negative. The Buddha then admonished them, 'Just as you had not seen him killing, so also he had not seen those living insects. Besides, being an Arahant he had no intention of killing, and was not guilty of committing an unwholesome act.' On being asked why Cakkhupala was blind, the Buddha revealed the following story to explain the nature of kammic effects."


This is the Dhammapada Story that gives an explanation to the first verse of the Dhammapada:


  "All mental phenomena have mind as their forerunner; they have mind as their chief; they are mind-made. If one speaks or acts with an evil mind, 'dukkha' follows him just as the wheel follows the hoofprint of the ox that draws the cart." The Buddha, Dhammapada verse 1


The Dhammapada Stories for the explanation of the Dhp. verses