Would a minor talent using his power to read surface thoughts or emotion be in violation of the Laws of Magic, or are those meant for wizards only?
There are two parts to be discussed when talking about the Laws of Magic in DFRPG - taken liberally from (YS232):
The Social/Legal Aspect (The White Council and how others look at the Lawbreaker)
A lot of what is covered by the rules of magic is in the details, and who is interpreting it. that is nuance, to be decided in game. There is a very great latitude given to Wardens to be "judge, jury, and executioner". Even the fact of not being a mortal is not absolute protection from this latitude, i.e. if they come after you with deadly intent, once the sentence is carried out, it's a bit beyond the character's care whether they were on the right side of history or not.
However, The White Council has made it clear that this does not apply to mortals. And in the case of crimes that have victims, i.e. mind reading, whether the victim has a soul is also a part of the equation.
This is covered in (YS233), i.e.:
Ultimately, this decision should be made to suit your own sensibilities for your own game. The best interpretation is the one you feel will work for you instinctively, the one that will generate the kinds of stories you’re looking to tell.
The Natural/Metaphysical Aspect (Magical Principles that cover Lawbreakers)
The DFRPG covers this in concept also, rather than in RAW. The consequences are spelled out. However, again, what constitutes breaking for the magical principles is something that should be discussed and decided on as a group.
Who determines that a character has crossed the line?
This is something that a gaming group should decide on as a policy for their specific game. Many groups will want the GM to be the arbiter of such things, and that’s fine. Others might go for a majority consensus of the people at the table.
So the short answer to your question is- what does your group think?
Answers to these questions will ultimately shape the feel of your campaign and your city, and should not be made lightly, but answered with that ultimate goal/vision in mind to create a living city that is based on Jim Butcher's books, but ultimately your own.
Either talents would break the The Third Law of Magic and thus expose whoever uses it to mighty retribution if they are caught. The Laws do apply to all who do magic, and not only full member wizards as was demonstrated by Harry's apprentice being under the Doom of Damocles.
Of course, this applies to human (and human only) and not to anything with supernatural blood in them. But being a member or not of the Wizards is utterly irrelevant. In fact, even knowing about other wizards is irrelevant.
Also, keep in mind that the Wardens (Harry and the new ones might be exceptions) are all old wizards, set in their ways, and all of them take a dim view of transgressions. Harry was cutting it really fine (and was told so) when he raised an undead animal.
Empaths: NO. Because the character is just picking up on the emotions another entity is exuding. The way Butcher writes about it, emotions and not just external but are also things that are being externalized by subconscious expression and a person's unconscious physical communication, and picking up on those signals just means a character is sensitive, or hyper-sensitive to those ques.
Telepath: Not Specifically by Technicality, BUT in most functions YES. From the viewpoint of the base canon (Jim Butcher's Dresden Files novels), I'd say that just being to communicate mentally, via a thought broadcast is fine, but that's only usefull if around others who want to and are capable of recieving the message. Harry and Elaine communication this way in Blood Rites. HOWEVER, anything that has to do with reading another person's mind like "Hear Surface Thoughts" would break the 3rd law of magic.
Neuromancy to reveal thoughts gets into the dark gray area of The Third Law (Never Invade the Thoughts of Another) pretty rapidly and turns to Black Magic as soon as you read a thought of another that doesn't want their thoughts read. p. 238 Your Story, paragraph two of the The Third Law section:
"...To read someone else’s thoughts, you have to cross one of the most fundamental borders in all of creation: the line that divides one person from another. When you break into someone else’s mind to listen to his thoughts, you’re disrupting the natural order of things..."
I'd say that most Telepathy to read other peoples minds would qualify the character for being a Violator of the Laws of Magic (Law Breaker Power) almost immediately, and as such would get the Warden's attention and ultimately end with a gruesome beheading.
Consequently, casting mental communication spells appears to be quite simple according to the canon as it is something that Harry can do with Elaine with no preparation and on the fly while having another conversation with a 3rd party (White Night). Probably a 2 or 3 shift spirit evocation that lasts for the length of the scene that allows you to speak mentally to one other person who can also cast the identical spell. As such a simple, non-invasive mental communication spell wouldn't require an extra supernatural power that costs refresh.
I'd work up this form of "Legal Telepathy" as a simple Evocation spell (within line of sight) with low power so that it couldn't accidentally bypass another's mental defenses even on a poor roll thus insuring that it doesn't break into their mind unwanted. I'd say the spell would use the sensitive side of the Spirit Element and by extrapolating the sidebar info on veils (spirit blocks), I'd feel it justified to extend the duration out to the length of the scene without requiring extra shifts of power to extend the duration. Alternately, if you want to do mental communication over a greater distance, you'd have to do it as Thaumaturgy, which Harry also did with Elaine later in White Night by tagging the aspects: "I know Elaine's True Name" and "I've Soul Gazed Elaine" in order to extend the range of the spell.
"Legal Uses of Telepathy/Neuromancy": Other than the communication spell above, in the books, Harry and Molly practice mind magic vs each other to build up mental defenses to invasive mind magic, but they can only "legally" do that because they have each other's express permission. Harry even states that the wrong move and lack of restraint during that sort of practice could potentially be disastrous. (Ghost Story)
If you want to have a Telepathy-like aspect in the game and have it be Kosher by the laws of magic, but still have it pick up details of PC's or NPC's that aren't open to mental communication then I'd focus on an building a supernatural ability that makes use of assessment actions or a specific application of The Sight instead of a "Telepathy Ability". Perhaps an ability like "Sensitive Mirrors of the Soul" that would allow a person to trigger a Soul Gaze more easily, which in practice reveals aspects of the characters in play, the balancing aspect being you let the PC/NPC see a bit of you back per normal Soul Gaze rules.
Not really, if you've read the books, remember Molly can read emotions and thoughts, and while she is a warlock, she still did it after she became Dresden's apprentice, and Dresden knew it. I think it's considered an area of gray magic, so you should tred lightly, and try to avoid casually using it around wardens.