[QUOTE=aktill;8017516]
You’ve said it tends to scoot forward. To generalize, either it fits but you’re saddling up too far back (unlikely), or the forward portion of the bars is too wide.[/QUOTE]
I always make sure that it is set back when I saddle him. You have put into more succinct words what I have not been able to describe very well about the forward portion of the bars.
You’ve said the back bounces. That either reinforces that the front is too wide (diving down at trot), or you’re only using the forward cinch like most people (lots of floppy saddles out there). A full double rigging is dysfunctional without the rear cinch, but that’s only an issue if the tree isn’t a great fit.
I do only use the front cinch, snug but not tight. How snug would I need the back cinch to make a difference? I have used it in the past and had it where it is just against his sides but I can easily slide a hand under it? It’s hard to adjust sometimes with the holes on the billets–one hole seems too tight whereas the next seems too loose 
The lack of craftsmanship in the photos you’ve posted isn’t impressing me much, but it doesn’t look dysfunctional.
Could you tell me what you see that makes you say that? Compared to other saddles I see at the barn, had thought mine seemed a little better made, but that could just be what I have to compare it to! There is not much to see for Western saddles down here in south Florida 
Finally, where the cinch lies is to some degree a personal preference. If you’re roping heavy cattle (unlikely), full double rigging is a great choice. If you just like double, then run a mohair cinch front and back and do both up (the rear being mohair will give more, and reduce the bouncing of the rear of the saddle). If you want to run a single cinch, we’ve already talked about the options. A Y-cinch will work fine too, but will act identically to the long latigo, v-rigged version.
Not sure if that helps, but with a saddle that really fits, you don’t have these issues.
Someday I will have a saddle that really fits, but for now, this is what I have to work with and I am trying to make it work the best I can for my horse 
This saddle was “supposed” to fit from what I went through in ordering it. (Down here it’s Circle Y saddles or less)