Why can't you achieve the equilibrium exactly in the middle (K=1) when you add enough heat/energy? My reasoning would be that given the high amount of energy added, both the activation energies of the reaction from left to right and right to left are excessively surpassed thus both directions are as easily achieved. Please correct my reasoning if this is wrong. Thanks!
There are indeed reactions where the equilibrium constant passes through unity as a function of temperature.  The water-gas shift reaction 

$\ce{CO + H2O &lt;=&gt; CO2 + H2}$

has an equilibrium constant that gradually decreases with increasing temperature (it's slightly exothermic as written), and the constant is close to $1$ at $\pu{800°C}$.