Turning a spell like ability to a natural attack does not alter the time required to use it. You could take quicken spell like ability to reduce it to a swift action. The problem is that the ability does not last long enough to threaten with. Without the ability to threaten you cannot make an AoO. This ability was not designed for what you want to do, and I don’t think that there is a way to make it do it.
Quicken spell like ability can turn it into a swift action, so you don’t have to waste a standard action. Since the target does not get a saving throw and the dazzling lasts for a minute that is not a bad use of a swift action. You could use this before you act as a minor attack and debuff. But a better use would be to use it as a follow up attack on something that is very close to being taken down. If your normal attack brings the target to where it has only a few HP left, use shadow strike to finish it off. There is no reason you cannot use a swift action at the end of your turn. The feat will cut down the number of uses to 3 so it may not be worth a feat if the character is feat starved.
Use a CONDUCTIVE Amulet of Mighty Fists.
EDIT: This wouldn't be so great for AoOs since you can't use swift actions off-turn. If you attack with weapons you could make it a +1 Conductive weapon, or the same for the amulet as suggested above.
If you go with a conductive weapon don’t bother with quicken spell like ability.