Are you kidding? That's awesome! Pass that crow to someone who deserves it. ;)
To answer your questions, I never pin past the first two pieces. I find them cumbersome. Once I've got the first two patches sewn on, I feel like the piece is stable enough to simply place the next one and hold it while I turn the piece over to stitch. Try that. Check it once just before you put it under the needle in case it slips a bit. Even if it does, you should be able to see if you've got the next piece on there straight enough to sew. If you have your ¼" line marked around the outside of each piece, you shouldn't need to worry about a special foot, just follow that line making sure you've lined up the two blocks carefully. It's nearly foolproof. (Not that you're a fool! LOL)
I have no idea why you tried to square it up. LOL (did you not have a ¼" line marked all around the pattern? If you have that line, it makes it easy to trim it right. You just cut ¼" from that sew line.
You're doing really well. No way would I have tried something that hard right out of the gate. I stayed with some really simple pping for a long time. I'm a chicken. LOL