...It burns hotter and quicker.
It does, indeed, burn hot, and then the comparison is "hotter."
However, it burns quickly, not quick; and the comparison is "more quickly."
...He reacted more calmly -- not "calmer."
...It runs more smoothly -- not "smoother."
Just a little grammar -- a very common grammar error, I might add -- information for the day.
Happy punctuating!
Margie