I am not a huge rule person...I like guidelines, but I like the ability to work through things, to adapt a training method to suit myself and my students.
Do I believe the dog should do all the adapting to be what WE want...honestly? No. Dogs are individuals. I see reason in learning what they need.
Your job as the trainer is to figure these things out...to work WITH your dog...shaping them into what you want in a training partner. I think when you tell someone DO NOT DO THIS...you are creating a "rule" in their minds...not doing something with ONE dog, might be a bad thing for another dog.
Not all things will work for ALL dogs...but you don't know until you try them. Leave your options open, really think about something helping your dog. Dogs are amazingly good at figuring things out :) Guidelines are great...they help us stay on track and help many who are starting out and don't have that "feel" for the training. But even as a novice, don't negate things just because someone says it's evil...if it is physically harmful to the dog, sure, but if it is just a little different way of doing something...remain open.
When I am teaching, I feel like I am telling people how I would do things, they can choose to or not choose to take what I provide. If what they do works, GREAT!! I will see that, and many times add that to the ideas I have :) Learning from my students is as important as what they learn from me!
Here is a list of things that I have been told in the past--that I have actually USED to my advantage in training:
Never chase your dog (Lynn LOVES THIS)
Do not tug (ALL my dogs tug)
Limit your dogs play with other dogs (Worked great for Crackers to play with others)
Teaching a dog to grab a toy won't build tug drive (dogs need to learn to use their MOUTHS, grab things, etc...if they don't, they won't grab a toy...once they are grabbing the toy and know they can grab things...it actually does help some dogs)
Don't let your dog get over aroused (I use this ALL THE TIME)
Never push a toy in a dogs face (aka Maya--she LOVES this!)
Don't pinch a dogs butt to get them to play (Maya, Even, Zip, Gator and Lynn)
Don't rough house with your dog (Use this all the time)
Time outs ALWAYS work (nope...not in my experience--there are times it is so demotivating it's not worth it--causes more issues...)
Correction is BAD (all I say is go work your dog on stock and see correction in action...it's amazing when applied in the right manner and I have never seen a more devoted dog than a working sheepdog to their owner)
Dogs must have both toy and food drive (nope...you can adapt to that)
Dogs cannot be high drive while using just food (have you ever seen Zip work for food?? LMAO!)
All (terriers, northern breeds, hounds etc etc etc) are tough to train (nope...I've seen and worked with some really amazing ones!)
I am sure there are MANY (and I would love to hear them in the comments section!) but the point I am trying to make IS...Don't let someone tell you something won't work and you accept it with blind faith. If your mind tells you that it MIGHT, try it? Observe what happens? What does your dog do?
THEN you can decide for yourself, what works or doesn't. I see no harm in asking questions of your instructors, why they want you to try something or not try something...I don't get offended when my students question me, they are trying to figure things out, how it will apply to their dogs. I like it, makes me see my students are thinking through things!
I think extremes on any spectrum ( political, social, dog training, child rearing etc) can be very scary...
Remain OPEN to new ideas, remain open to old ideas...