bearisgray

I learned how to piece the same way you did - and it was a valuable class to me.

I still like to have my pieces cut so that the threads on the outside edges are parallel to the edges (on grain)
I think it matters - but many people say it matters not.

I also am adamant about washing everything washable before cutting it. (Except the thread - perhaps if I could figure out a "tolerable" way to do that, I probably would.) I have had enough unpleasant surprises to make it worth the effort for me. Others have said that they have never ever ever had any problems with using unwashed fabric.

If you wanted to, you could mark every seam so you stopped stitching 1/4 inch from the edge (like when hand piecing), Then you could hand tie the threads at the end of each stitching. I am not a fan of backstitching, because then I get a "wad" and never seem be able to stitch back "exactly" on the same stitching lines.

Different things matter to different people.

I do think quilts soften up with use and washing.

When chain-piecing, I sew air for about four stitches between each pair of patches - I feel that leaving a couple of stitches hanging between the pieces after clipping them apart makes them stay together better than when I clip the threads exactly at the edge of the fabric patches.

So far - you've seen several viewpoints on how to make a quilt -

It is also okay to mix methods on one top - example - some seams pressed open, some seams pressed to the side, etc.