I always do because I'm scared it will come apart if I don't.

No, just shorten your stitch if you are worried it will pull out. The next seam or over - sew will lock the stitching. It would be too tedious to backstitch as you are chain stitching.

I do because I have had too many seams come apart. It is a habit. I do it even when I am chain stitching.

If I am putting the rows of a block together I make small stitches @ the begining and end of the row to secure.

i do but that is a habit from sewing clothes , sometimes when i chain stitch i catch myself doing it

You can read all about leaders and enders here. I use them but not the way she does, but someday I plan to cut all of my small scraps into squares and make something with mine.

Good to know.

I don't back stitch like what you'd think of.. 3 stitches forward, 2 back, then forward again.. But what I do is I hold onto the block just a second or two and so take two or three stitches in the same place or nearly the same place.. then I let the feed dogs do their thing.. Not a true back stitch, but it holds very well.. I never actually backstitch any seam that will have another seam crossing it. I do back stitch at the outside edges though.

ME TOO

I rarely back-stitch when piecing, however sometimes if I want to be sure a seam holds to withstand tugging, I will.