I go to the sewng store like JoAnn's and get the seam tape. It comes in different widths and will hold really well while you sew...........and won't ooze out on the edges.
Got the hint from Kevin King who happens to make a LOT of wallets
when you enter the hole with the needles and thread......make sure you do it the same way every time.....otherwise the threads get crossed in between......doesn't seem like much but it makes a big and noticeable difference
Watch Nigels video!!!
another thing to remember is not to cross or change direction when sewing. it can make your stitches look off. I did notice a few places where this occurred on your piece
The needle has nothing to do with the presser foot marks. Try loosening the presser foot tension and see if that helps. Too loose and it won't feed properly though!
that is embossed or tooled leather. the untooled or nonembossed areas will look raised like that. and that looks like an arm guard or similar item and is bent into a rounded shape
Hope that helps
Mike