Which AP site are you referring to? apstylebook.com uses topic headers but not headlines. www.ap.org follows our standard headline style, as far as I can see.

Just the Biden administration is fine even if it's the first reference. But follow it shortly with his full name and title:  President-elect Joe Biden said Thursday ... 

AP style doesn't use italics. We don't have a specific style for this. I'd probably use capital letters and no quote marks: Brand X's Glowing Faces collection.

First, do you have to use the direct quote? Often it's better to paraphrase, and save the direct quotations for the truly quoteworthy.

If you do need to use the quote, it's Nov. 3 if the source has spoken the words. Here's the relevant section of the quotations in the news entry:

When quoting spoken words, present them in the format that reflects AP style: No. 1, St., Gov., $3. But quotes should not be changed otherwise for reasons of style. If the speaker says towards, do not change it to toward.

When quoting written words, retain the style used by the writer; do not alter the written words even if they don’t match AP style.

We'd rewrite!

We wouldn't capitalize downtown in any use (except as part of the proper name of an organization); it's considered a generic term. Of course, you could choose to capitalize it locally. If you do, I'd suggest treating it the same whether as a noun or an adjective.

Pre-populate, following guidance in the pre- entry.

Pre-fill, following the guidance in the pre- entry.

I'm not sure what is meant by pre-fill your hot tub. I'm guessing "fill it before you get in," but it's not entirely clear.
 

Either is fine. The table below is more natural; it's the way people speak. The below table sounds more official, which isn't necessarily a good thing in this case.