What will happen in an exothermic reaction if more than required energy is given? I mean, will it produce even more energy which will be highly dangerous or nothing will happen according to Le Chatelier's principle (as we are trying to carry the reaction in an opposite direction)?
There are two separate effects we need to consider here: thermodynamic and kinetic.
Let's assume you are only providing the energy thermally. So providing more energy means increasing the temperature (T). Thermodynamically, if a reaction is exothermic, and you increase T, the reaction becomes less favorable (assuming it stays exothermic over that temperature range) according to, as you mentioned, Le Chatelier's principle. I.e., the equilibrium shifts to the left.
However, we also need to consider kinetic effects. Here, as you increase T, the rate of reaction increases, and thus the rate of thermal energy production increases, thus further increasing T, thus further increasing the rate, and so on, leading to the thermal runaway effect that Buck Thorn mentioned in his comment. I.e., we get a positive feedback loop.
The equilibrium constant depends on temperature, the only thing it depends on. For an exothermic reaction the equilibrium constant will decrease ie shift towards the reactants side
Also consider kinetics as described above