954 Hi Michael,
To answer your questions:
1. It is fine to move the platforms outside. You might actually be better off if Ellie doesn’t mess up in the home. The idea is to be able to teach her the full set of rules that goes along with it, without it being too overwhelming to you or her. If neither seemed overwhelmed you will be good.
2. I don’t recommend using a martingale for phase 2 obedience mostly because the collar needs to be used with too much force to motivate the dog for correction purposes. A good alternative to the prong collar is a “good dog” collar. It needs to be used with a little more force than a prong collar to motivate the dog, but it is much less likely to overcorrect the dog if you misjudge. It is great with young dogs, and you can’t go wrong starting phase 2 with it.
3. Running free is fine as long as you feel the area is safe and you don’t have a dog that is the type to “take off”. Refer to the “dog training trinity” in the obedience section of the literature and work on the “+” and “D” stuff and you will have a huge head start.
Hope this helps!