I'm definitely no expert but here's my thoughts. A tree's goal is to get to sunlight. That is their "food". Understory trees in the forest do not grow straight up, they go in the direction they need to get sunlight. The bricks you have surrounding the trees block most morning and afternoon sunlight - the only time it's in full sun is when the sun is straight overhead. In which case in an upright tree the upper leaves will shade the lower leaves. By growing off to the side it can collect more sunlight to feed itself. Once it starts growing above the bricks the new growth might right itself.. if not you can try cutting the main shoot just above a bud pointing up and let that bud take over. The way to make a tree grow stronger is to let it sway in the wind. Of course depending how strong the wind is it can also permanently deform a tree. And some trees are naturally stronger than others. I don't believe that staking it aggressively now will cause any permanent harm. Once this growth turns woody and starts to build strength you can leave it staked but loosen it so that it can sway a little bit. Just make sure as the tree grows not to let the stake ties strangle it. Eventually you'll be able to remove the stake. Also remember that when the trunk is 6 inches in diameter, you will not be able to notice any minor waviness that it will have after staking. Best of luck to you.. that looks like a challenging environment for gardening.

No, the scorched branches are probably dead. But they're likely to have died off anyway with being shaded out by higher branches as the tree grows (that's normal for pines). Branches that stayed green will be OK. Resin

There are several species of pine tip moths which feed on the terminal growth. They do little damage to the tree, but are so common that most white pines eventually form multiple leaders just as yours has done. You can do as jean001a advises, but chances are the same thing will happen to the new single leader. The pines currently growing with a single leader are vulnerable as well. It is possible to spray for the moths, but this becomes increasingly difficult as the trees grow taller. Most people just accept that their pine trees will eventually assume the multiple leader look.

I would let it do it thing. It will branch when it is ready. When it is about 5 feet tall you will need to take a bud from the top and graft it to the bottom of the tree if you ever want fruit. wood maturity is messured by the tree as the number of leaves that bud is from the roots. At 5 feet you may have a leaf node count of 100.. the leaf node count will start at 100 even though the bud has been moved to the base of the tree.