Chris-
How long have you vaped?
You do know a "cart" isn't equal to 10 packs of cigarettes or whatever BS they try to tell people, nothing against myvaporstore, but believe me, many people have fallen for it.
A cart lasts me about 10 puffs. I used to smoke 2 packs a day and I don't anymore. I do vape heavily though. I drip instead.
By the sounds of it your overfilling your carts. Probably drowned your atty (that's why you're not getting very much vapor) and probably why it leaks.
I can say from experience that juice has nothing to do with the temp of your atty. Speaking of which, my atty get's hot too. How hot, I don't know, pretty hot. It's supposed to.
Anyhow- try two or three drops, blow out you atty and try a fresh battery and tell us how it goes.
Bruce