Fire
I run uphill faster than downhill
Fire travels faster going upwards because hot air is pushed upward and cold air is consequently pulled in from underneath (so, more easily from the downhill side), which pushes the fire uphill.
People don't touch me, that's chill
Usually, people don't touch fire. That's chill, because if they did touch fire, it wouldn't be very chill anymore.
I tend to destroy more than create
Fire does create, but it mostly just destroys, specifically, whatever it's burning.
But I can be used to make something great
Food, I guess. Also glass. And various other things.
I am loud and I eat, but I have no mouth
No mouth. But fire is quite loud, and I suppose it "eats" fuel (and oxygen).
I travel around, west, east, north, or south
Well, fire spreads indiscriminately of direction.
People hate me, yet love me as well
Forest fires, building fires, any unintentional fires really suck. But we also couldn't live without it to warm us, help us travel, cook food, etc.
The smaller, the better, that's what they tell
Smaller fires are better, in general; large fires get out of control and then cause damage and death.