-16p12-----12h16p16------- etc

The only problem i'm having on these is with the 14th fret, when i lift my finger from it, it sounds like a pull-off. Even though i try to lift it as straight up as a can, but it still seems to ring. Especially on higher tempos, i can't do it clean. So it sounds a bit messy, since i can clearly hear the free string there, even tho it's quick.

It's hard to adjust my finger's so that i can plant it straight down on the string, since i need to move to hammer on/pull off right away.

is it possible to learn to mute that string by palm? I tried it, but seems impossible. How do you guys play things like these?
Try using the very tip of your index finger of your left hand to mute that string. And yes it is absolutely possible to mute it with your right hand as well, but without knowing how you position your hand I can't really offer any advice except to experiment.