Thanks for all your input. I also looked at hundreds of different Stan and Todd signatures. All of that, combined with a lot of what you said, made me feel extremely confident that these were not genuine signatures.
One thing I noticed in EVERY Todd McFarlane signature, is that he always starts his R from the very top of his A. Literally every single signature I looked at was identical in that way, but not this one. The connecting line from the A to R starts in the middle of the A, not the top. Looks like a lot of overall hesitation in it as well that didn't look consistent with the other signatures I saw. It's also not easy at all to find books he signed "Todd" instead of "T."
Stan's just seemed off to me right from the get. For starters, the angle seems off to me. Every signed book I looked at, which was literally hundreds from all different eras, was signed at a more upward angle. Also I could not find a single signature where the last E in Lee is smaller than the first. That seems like one tell-tale sign in his autos he always made that E bigger going into his underline back to the front. Seems to be on the small side as well. Overall just doesn't look like a confident signature, more like its drawn.
Also did some digging into his feedback as a buyer. Found some very suspicious times of purchases from sellers that seem to have a large selection of duplicate comics. A lot of which had obscure copies of Spawn, Spider-Man, and other Marvel comics. Of course none of them had Spawn #8 (probably because he bought them all to practice on haha) Also looking at his feedback as a seller, he's sold no less than 50 signed Stan Lee comics (none of which are CGC) in the last 6 months. Which also happens to be the same timeframe as his feedback as a buyer from the duplicate comic sales.
I ended up asking to cancel the order, and voiced a few of my concerns over the signatures. He was not happy to hear any of that, and proceeded to tell me he's been on the auction site for 17 years and has never had negative feedback or questions about his signatures. At first said normally he would cancel the order, but because of my baseless accusations, he was leaning towards not. We went back and forth a couple times, and I ended up telling him I was tired of arguing about it. I was going to chalk it up as an L, learned my lesson, and move on. But that I was going to be leaving a detailed feedback. That may have scared him off, because he relisted the comic and told me he would be cancelling the order on Monday.
End of the day, I take the fault. All the research I did after I bought the comic should have been done beforehand.