Skye, I am so sorry that all the "advice" made you feel so conflicted. It is bound to happen. And certainly don't feel pressured to go all dressagey. No need. However, it might help to get a bit of instruction at the beginning.
Also, you don't hvae to ride dressage to encourage your horse off the forehand. If you look at videos of many of the best western riders, their horses are NOT on the forehand. So, it can be done in any tack.
You cannot MAKE your horse carry themselves on the hind quarter by virtue of tack of any kind. You can only encourage the horse to themselves change their own way of going. You don't shape them like clay, you ask them to change their own bodies. They know how to shift onto the rear. They do it every time they accelerate or go uphill, or stop suddenly and change directions, all visible in pasture playtime.
I think what you are thinkiing about is encouragein your horse to do this sort of self carriage while you are onboard. This is certainly a good idea , as it will prolong the useful life of your horse if she is not hard on her forehand.
the thing is, it is easiest for a hrose to go along on the forehand; requires the least amount of energy to move forward with a baisically "falling forward" method of carrying that rider.
Your job is to encourage and insiste, little by little, that she work more in a "carrying" way, with more weight in a vertical carry (hocks flexed and underneath) rthat than a horizontal "run forward" way of moving.
Dressage is theorectically meant to build this correct way of carrying a rider, in a step by step manner.
I dont' think I can explain it all on the forum
But you are right in that it is fundamentally asking for more push from behind while disallowing that energy to just fall out the front, thus changing horizontal energy into vertical energy. Make any sense?