Thanks for the comments.
I guess I forgot to say my goal was to create shelving that was both stronger, 1/2 the price of wire shelving, while still being easy to assemble, and I accomplished my goal. We all know there are ways to make it straighter and stronger. I'm not going for the strongest shelf I am going for the cheapest while still outperforming the wire shelving.
You've got a good eye, thickness of the plywood was 1/2". I had it laying around so long I thought it was 1/4" for some reason. I guess I should have measured

.
I think it's easier to work with the smaller pieces. My saw has the measurements marked and you can even use your scrap pieces for this which is what I did making it free over using an entire long piece. I would argue it's easier to hang the separate pieces over a long piece because you do not have to worry about bowing and pre-drilling the holes in the right spots potentially missing the studs and when you put very long shelves you don't have to mess with full 8' pieces.
Did not check the level. But I just checked it font to back it is perfectly level. The plywood is slightly bowed here. I used old warped plywood that I got in a craigslist trade.
There is a slight bow in the center due to either the furring strips or the ply being warped. I usually put the bow facing up but I just didn't think about it this time.
I thought about using plywood or osb for the diagonals but the furring strip seemed cheapest and easiest.
You're right about furring strips being warped. I bought a big batch an used the warped pieces for shorter lengths and kept the straight ones for the long runs. I am not rich so yes I need to save every dollar.
Thanks again for the comments I appreciate you all taking the time to check it out. Feedback on the video is welcome as well. Like was it too long too boring ect... I'm thinking about making 2 videos for every project a long video and a short one.