I was self-taught quilting before the rotary cutting revolution. The books I had in the 70s were basically just black and white diagrams of the blocks and very little setting information, zero actual directions and no yardage/cutting information. As a result, I press my seams open figuring if it is good enough for garment construction and the wear and twisting that clothing/laundering takes it would be good enough for quilting. I've had zero issues pressing open (the fabric in the middle wears out long before the seams do) and although for the last 20 years I've tried embracing pressing to the side and just can't. It's lumpy. I don't like what happens when you have two white pieces sewn together. I'm more precise open.
I feel that pressing seams to the side is an artifact left over from hand sewing is not needed with machine sewing. Also, there was a period of time around the turn of the century when American fabrics were not very tightly woven and maybe it was needed due to flimsy fabric, then lesson was passed on to the next generation and so forth. We have electric power and irons now, they don't have to be heated on the stove any more...
The only time I backstitch is at mitered corners, otherwise I chain stitch all the pieces and trust in my small stitch length to not give me problems. I do a lot more pining than some people do, I feel I get better results. I use quilting pins perpendicular to the seam but well down below the seam allowance so the needle is nowhere near the pins.
As far as softness goes, all of my quilts are pretty stiff when first made. Takes about 3-5 washings and then they just get more comfortable as they age. One reason for stiffness is that with the advent of home Long Arm machines and wide throat machines, a lot of people do a lot of quilting and typically they do it on a pretty firm batting like warm and natural. I prefer a bit looser quilting and thicker/fluffy acrylic batts, but sometimes warm and natural is exactly what I want.