@PA_Penjing
Not meaning to be harsh, but your tree looked best in the first photo, before you started hacking off branches.
I do like this view:
I suggest you slow down. Or get 5 more similar size jack pines so you can alternate who gets "tortured" this summer.
1. Pines in general, even young pines should not be repotted more than every other or every third year. Older trees should be repotted less often. Allow one full growing season with NO pruning for recovery after repotting.
2. Wiring - it is normal for pines to have it take a decade for a branch to hold it's shape. Normal routine is place wire, bend to shape. Tree grows 2 years, wire starts to cut in. Remove wire. Tree starts to spring back out of shape. Re-wire, being careful to either wire with coils opposite direction, across grooves left by first wiring, or carefully wire with wire parallel to old grooves, so to avoid making wire scars worse. Allow second wiring to be in place until wire starts to bite in. Anywhere from one year to 3 years would be typical. Then remove wire. If tree springs back out of shape, wire again. This process of cycles of wire and rewire will go on for a decade or more. Pines stay flexible. They are not like deciduous trees.
3. Young trees, such as this pine, need to grow, in order to thicken trunks and to have the energy to make back buds and to ramify branches. You should have kept the low branches to help thicken the trunk and to help maintain vigorous growth. Even if the will be removed for the final design, keep them - just wire them out to be out of the way. Then wire the ends up so they keep growing.
Pines "compartmentalize", you can have one branch lanky and juvenile looking as a "sacrifice" and a branch elsewhere that has been pruned for ramification and short needles. The lanky "escape branch" will help keep the roots and sap flow vigorous, while the other branch is trained for the final design.
All in all, your tree is "not bad" but would have benefited from "slowing down your roll". You are over-working the tree. Give it recovery time. Try not removing any more branches. Even if you don't see it as part of the future design, let it grow as sacrifice branch.
Your approach graft could have worked if you left it in place for 3 or more years. Though if the branch died, it was likely it was bent too sharply, like kinking a hose, so sap could not flow.
So get a couple more jack pines, so you can let this one recover between techniques. I am encouraged by your enthusiasm. Don't despair. It will come together in time.