Ok... let's shift semantics just a bit and understand that we don't "Read Minds" but rather "Divine Thoughts"... this may sound trivial at first, bit it is a very important difference and one of the biggest reasons a "Mind Reader" asks that you focus on a specific thought vs. a Psychic that simply goes with his/her gut. (please don't turn this into another "prove it to me session".)
Secondly, let's look at the above misconception of "getting it right every time"... something that an experienced performer of Mentalism wont do (on purpose most of the time) in that you come off as being more real and genuine if you make near hits and even deliberate misses from time to time. Only a magician and those still clinging to their magician's mind-set insist on doing material that hits and follows to a known conclusion each and every time... something typically known as "Mental Magic" vs. "Mentalism" but that's another can of worms altogether...
Now, as to the actual question put forward, as to if or not it is possible to divine the unspoken thoughts or, influence the thoughts of others?
Yes, it is possible.
Even the more cynical of the world knows about the peculiar syndrome known as ideomotor response and the FACT that legit science recognizes this as being the closest thing to true telepathy it can confirm. Anyone that's studied this phenomena knows that it can be used in dozens of ways and as such, you can replicate just about every major ability attributed to the traditional psychic and mentalist... if you're willing to invest some time into developing said skill.
There are likewise body-language techniques that can help convey attitude and action responses along side the proper use of words in conjunction with gesture. Though most see this as part of Neuro-Linguisitic science, I see it more as a discovered side to our more animal-based antics that some become aware of and see how to manipulate be it for the sake of good or bad.... via such methods I've run several personal experiments and found, along the line of the "old Jedi Mind Trick" that I can think and focus on the idea of getting a large drink when ordering a small and nine out of ten times, I get the size I was focused on... the impetus to this little "trick" stemming from a Docc Hilford manuscript I read several years ago and it's prove to be quite a fun bit of Magick here and there.
Discerning the thoughts, feelings and even images held to by another can likewise be revealed via gut level (intuition) reaction. This is spoken of in Millard Longman's PSYCHIC SKILLS WORKSHOP as well as Kenton Kneppers book MIND READING. Study these two tomes and you will be that much further down the road to reaching such a goal. BUT, you need to let go of the fantasy of such thing things if you are to be effective.
I teach this stuff to what's known as the "shut-eye" market (believers not aware of the magic methods) as well as magicians, I know either side of the issue at levels I wish I didn't at times, and both sides have their "fanaticism" that stems from personal preconcieved notions or "fantasies"... the more fantastic of course, seems to come from the Shut Eye market and their psychological need to escape from carnal reality and live out the idea that they are some kind of all powerful psychic... it's an unreal goal, far from what the true masters of mysticism actually taught about, and has little to nothing to do with healing one's own spiritual health... it's pure ego without the recognition of such.
We find a similar phenomena from within the magic world, but it's filled with more venom and denial, which serve as the "fantasy" than what we find in the believer's world. Both are extremes e.g. both are wrong and untrue; preventing you from seeing and being able to learn from the greater truth found when you can understand and work with either side of a concept. But that's just my own peculiar way of looking a life... always striving to find the middle ground and avoiding the extreme. You may want to think it over...
