Spraying powder over the tape is a boner maneuver for sure but the rest is not that bad from what I've seen. I totally understand your frustration as I have been there myself
. You can carefully sand and buff the drip out on the tailgate. The shop I use preheats all of my stuff before spraying the powder now and it seems to turn out better than before. It's still not 100% perfect though and always has a flaw somewhere. I've learned to except that it is not going to look like a "show" paint job but won't scratch like one either. I think it is pretty difficult to apply enough powder on all edges without it building up too much on others hence the drip. Depending on how thick it is, you may be able to sand and polish some of the orange peel too. Just don't try it on velvet black because it becomes glossy really quick!