I think your cinch is the right size. If you go any bigger than it interferes with the vein that's on the barrel of the horse. My Vet told me 80% of people have to big of a cinch. You don't base the cinch length on the amount of leather left.
I've never heard that. So please explain why it would matter if the cinch is pressing against the vein, or if the latigo is pressing against it? No matter where the cinch is, something is going to be pressing against that vein.
I use synthetic cinches because then they have cushion behind the ring so that the ring doesn't press into the horse. Expensive? Yes. But it holds up well and I like how it fits my horses. Professionals Choice SMx VenTECH Western Cinch
Now I've been told, where you say the cinch should go, that that ring is now going to interfere with the horse's elbow, and the cinch rein should always be above the elbow.
But I do greatly agree with making sure you "pull up" on your pad before tightening your saddle, so it doesn't overtighten the pad on your horse's withers and back. Snickersandme:
That saddle seems to fit a little bit better than the last one you posted, but I think we can still do better. Plus, from the way that saddle flares up in the back tells me that is a cheap cheap cheap saddle.
I guess I figure I wouldn't want to walk in $10 sneakers all day every day. I'd rather have the cushion and soft $100 Nike shoes! Same with the horse. A more expensive quality saddle is going to be more comfortable (provided it is fit correctly) than a cheap one.