I'm working on my tapping and tremolo/alternate picking skills. It seems whenever I try to slowly speed up on tapping, I end up going from slow to really fast. And when ever I tap fast, it sounds like I am just flicking the string, instead of the fretboard and flicking off. So basically just hammer ons/pull offs.

I can tremolo/alternate pick single notes relatively good. But when I try to pick more than one note, I end up playing the same not multiple times before playing the next. Say I'm trying to play from the 15th to the 12th to the 14th frets on the high e string over and over, but only hit each note once during the run. I end up playing each one 2 or 3 times. I guess I'm saying my hands don't have the same coordination/timing. And I'm not even gonna get started on alternate/tremolo picking runs that invole more than one string.

So, I'm asking if you guys have any advice on practicing the techniques. I know this type of thread has been done hundreds of times, but even so I'd like your advice.
I'll pretend I can mod your amp but break it instead.
try picking any string as fast as you can controllably at a constant pace and just play something on that one string like the major scale or something
I know this advice has been given thousands of times here, but the answer is to slow down as much as is necessary to get hands in sync, and for you to have more control over your playing. Once you've got it down at the slower speed, then you can start speeding up gradually, but watch out for the old problems creeping back in, and if they do slow down again for a while til the good technique is a bit more established.
^ Ah yeah, I forgot to mention that in my post. A metronome is a must if you want to develop good timing!