The white stitching looks like the back side (wrong side) of a coverstitch, not serge. You need to find someone with a specialized machine for that, as most 3/4 thread sergers won't do that, and most alterations tailors don't buy that piece of equipment because it doesn't get used a lot. You could have some luck if you just call around to lots of alterations places to ask if they can do coverstitch. There could be one that has bothered to invest in it.
A zigzag will do, but won't look anything like the picture.
You can easily and cheaply get clip in extensions in that colour. Don't paint your hair. It won't look good unless you actually dye it, and then have to live with it until it washes out. Rinko was very likely wearing a wig with blue extensions sewn in.
Tan ballet flats, or flip flops should be fine. You can just take them off when you take photos, or request that the photographer not include your feet in the pictures.