Hello. I have just started developing C41 on my own, so please forgive the ignorance. I'm using the Naniwa Color Kit S with Porta 400. I have a theory about the artifacts I'm seeing, but I would like to confirm.

1) In some of my negatives I have what seems to be a spotted discoloration that runs in a band across the edge of the film. I am doing two rolls of 120 together at once, which needs about 1000ml according to my canister, but I think the developer mix volume may be just under that, so the chemistry level inside the tank is too low, and the top piece of the film only gets saturated when I invert the tank every 30 seconds. Is this correct? (spottedBand.jpg)

2) In the second set of negatives I developed I measured the temperate of the bath outside of the developer container, not the developer itself. As as a result I think the chemistry may have been more around 38 degrees C instead of 40. Visually the film ended up very light blue. Are color shifts like this the direct result of temperate errors in the chemistry? (temperature.jpg)

3) Also, in certain rolls I have blue semi-circles and thick scratches (when scanned these become white marks since the color inverts). I've noticed this mostly on 220 film, which I have a hard time getting onto the reel inside of the changing bag. If I bend the film when loading onto the reel, would warps in the film cause these over-exposed spots, or is this due to something else? (scratches.jpg)

Thank you for the help in advance, I'm running through 50+ rolls for a project I'm working on, and would like to take care these issues for good.