All right! At least you're making progress with your assessments.
The miniscule pickguard gap that shows when you put your nose right up on the bass and the totally completely natural and normal wood knots are non-issues in my book.
As for the yellow spot, it would come down to how good it plays and sounds. If it's a great player and tone monster, I might overlook it, especially if it's something you can't see from more than five feet away. I have basses that are cosmetically perfect, but they have mediocre tone and playbility. I have basses with a tiny cosmetic imperfection that rock my world. After 35 years playing, trading, buying, and selling, and with a stable that includes over 120 guitars and basses, I can say with confidence that acquiring an instrument that is perfect in both tone and playability AND cosmetics is more rare than a planetary alignment.
I think this deserves careful consideration: Bass roulette is a hard game to play, but if you must shop long-distance internet big box warehouse, where they do not check the product and only pull and ship, this is often the result.
Whenever possible, you should be seeing the product first, especially if the standard is high and the potential for QC issues exists (which it does with nearly every bass and guitar made).
Guitar Center will order the product, let you come in and inspect it, and make your decision whether to take it home or not. You don't like it, they take care of the task of acquiring another.
Sometimes, paying a few more bucks to get a keeper trumps the time and energy spent playing bass roulette on the internet.
P.S.--FWIW, I have eliminated a stain on a white guitar using the gentle "gel" bleach. YMMV, proceed at your own risk.