The first few times I tried C-41, I was trying to keep it at the recommended 102 F. I don't know if my agitation was off or what, but I got some funky results on my 4x5 negatives not dissimilar to what you have there: weird, blotchy color shifts, etc.

Because of the short development times at those temperatures, it really has to be spot on perfect or you greatly increase your chances of screwing up your film from improper agitation, bubbles, etc.

I've been processing in handheld inversion tanks at room temperature ever since I killed an entire batch of 4x5 negs from trying to do it at 102, and have had quite acceptable results for both roll and sheet film. I've used both the Arista and Tetenal kits, 13.5mins in developer and 8 mins in blix @ 68, agitating for 5 sec ever 30 seconds.

Yes, it takes a lot longer, but if you're going to be hand processing, it leaves much much more margin for error.