My opinion...any type/weight thread is fine for thread basting. Any fairly large hand sewing needle that is easy to handle is fine to use. And as Mdegenhart says, about a hand-width apart in both directions. If you are machine quilting, glue is fine. I'm a hand quilter and don't use it so can offer to guidance there. And I mostly use safety pins for basting.
I suggest trimming off the edges of your borders to make them all square. Make sure your batting and backing fabrics are a good 3-4 inches larger than your top on all sides.
I baste mine on a table top. I use the big black binder clips to hold everything in place for basting.
Looking good so far. Good luck.