If you remember, veils also inhibit the perceptions of the person veiled in the same way and almost to the same degree as those who can't perceive the target. Only Molly seems to have no trouble with this. When she gets older, she's going to be a master of veils that even The Merlin won't be able to match. Her natural talent for them is beyond the experience of even some of the big dogs. Harry sees through them because he just knows her so well, and he's even admitted that he absolutely can't get through her veils, he just knows how she thinks so he catches her.
That said...you're right that it would be an extremely difficult thing to do, but more for someone who had already become fixated on conventional methods. Someone self-taught would have only slightly more trouble with that variation than they would with a standard veil. I think the potential benefits are worth exploring though. After all, it's easier to make a little bubble around one target than try to create a complete illusion over an entire area. In this instance though, it's a workaround on the 4th Law because it's not actual Neuromancy. The magic never comes in contact with their mind, nor alters their thoughts or mental state. That can't be done with all of them. Manipulating the dead (human dead anyway), even if using tightly controlled bursts of pure force to move them like puppets...is necromancy. Heck, the White Council probably thinks forensic medical examiners are necromancers waiting to happen if they ever developed talent.
As for the "drop em in the nevernever" method of killing...I don't think there's really a way to beat the 1st Law on purpose. Indirect death isn't good enough. If you use magic to knowingly cause circumstances that are certain, or even only LIKELY to kill the target, you're violating the 1st Law. The stain comes from the combination of intent and magic. You don't violate the 4th Law by using drugs and devices to alter someone's memory or force them to give up information, because there's no magic...even though there's intent. If you cast a non-neuromantic spell but it affects their mind anyway...no intent, no violation. If you blow up vampires with fire and don't know mortals are inside...no intent, no violation. Problem is, dropping someone into the potentially lethal nevernever specifically for that potential lethality, is still a stain on your soul. You purposefully act to end another's life, and you're calling on magic to facilitate it, even if the spell itself isn't what strikes them down.
Since most of the Laws only apply to what you do to mortals, doing it to vampires, fae, demons, outsiders, and other such creatures is perfectly alright. Frowned upon, but apparently not "bad for you" spiritually. The Wardens don't kill you for it, but they sure watch you like a hawk afterward...just waiting for you to cross the line and do it to a mortal.
The 1st, 6th, and 7th laws are pretty well untouchable. It's impossible to kill with magic intentionally without staining your soul, even indirectly. If you want the target to die, and you cast a spell that even so much as leads to their death, 1st Law violation right there. You can't do anything with the Outer Gates at all, so any spell that does anything involving outsiders even in concept will do the trick. I don't think looking for knowledge about any of it taints your soul, but the ideas are so dangerous that they tacked all of that on too. Seeing the future isn't chronomancy, it's divination. Sending anything backward though (even if it's not material but rather a specific thought sent back) is chronomancy (and neuromancy too, if it's a thought, even if it's to yourself)...and is a blatant violation under all circumstances (though I don't think that one taints your soul, I think it's more about the sheer danger of screwing with the past)
Ultimately though, the real purpose of this thread is to find ways to avoid the stain...not necessarily the Warden's blade. So, how do we not stain the soul with some of these Laws? Killing at all is pretty much out. You can't even use a burst of force to fling a knife at someone. You can't even enchant bullets to follow targets (even if that were possible, which I don't think it is). If you seek to inflict death or even harm (that directly though accidentally results in death) on the target, and use magic to lead them in any way to that goal, you're staining your soul.