How likely is it that my students using Creator-directed finger strength testing will connect with an imposter or their own subconscious trying to make something happen?

Connecting with an imposter will be unlikely as the intentions are to connect with Creator, and that does begin to confer some protections, provided level of belief is present. If this is done strictly in context of the Protocol there are protections requested at the very outset. So, the second possibility of misdirection would be from the subconscious stepping into the breach if Creator's impulse does not reach it, and answered through the body in a way to be useful. This is a much greater pitfall in terms of probabilities and will be the case for approximately two-thirds of the students. It is always a difficult undertaking, at first, to do something unconventional when belief level is being cultivated, and still somewhat shaky. Keep in mind, this very notion may be going against well-entrenched beliefs within the subconscious of the inscrutability of the divine, and the belief that Creator is unreachable and unknowable, because of cultural programming. The intentions are worthy. To have this in place for those who can do so successfully, communicating with Creator in this fashion can be extremely valuable. This is borne out again and again by the DNA ThetaHealers who use finger-strength testing to query their subconscious mind about what is going on with their client and this can be very fruitful if a connection to Creator takes place. It will greatly empower the range of information that can be accessed, and can come to be a very valuable guide in doing the work. Each would-be practitioner will have to sort out for themselves whether they are getting answers that make sense or not. There are always those who can fool themselves into thinking something is real, and then rely on it religiously; even though it is flawed and giving them false information, their naïve belief in it will override common sense. There is nothing you can do about this, as people are on their own to make their own judgment and will have to do the best they can.