How has pressing the seams open affected my outcome? Well, I pressed all the blocks last night and every one of them came out just about like that one. I bet out of 8 blocks that I will have just a few tiny, tiny slivers of squaring up to do. Would pressing them to the side have had the same result? Close but, probably not.
There's debate about whether it really makes it stronger and opinions that it's "old school" and based more on hand sewing the pieces.
I did a pattern but I am finding corrections as I go. I have to re-do the basket part since I found last night that I was not going to mess with 2 7/8" pieces, 7 3/8" pieces, etc. I re-drew the block and will try it tonight.