1. The links both get PageRank flow...
2. The link value gets divided, though, so it wouldn't exactly double the value.
3. The link extraction process might choose to only select one link from the page based on certain factors (perhaps ignoring some links not because they are duplicative but based on location, or other qualifiers)

Here is Matt Cutts talking about this very issue. And here again. It is the closest thing we have to an answer.

I think the reason for the "first link counts" is really an extension of an understanding of PageRank. Let's say a page has 1 outbound link. It gets 100% of the value passable by that page. Now, let's say the page adds another link, but it is the exact same link. Now, each link gets 50%. The sum total is 100%. It is as if the 2nd link were never added. But, this calculation changes depending on the other links on the page. Let's say a page has 2 links on it. One to you, one to someone else. 50/50. If you get another, you jump to 67/33. Slightly better. As the page increases in number of links, your additional link approaches a doubling of the first link's value. So on one end of the spectrum it is valueless. On the other end of the spectrum it doubles.

The other question is whether anchor text is counted for all links. Some experimentation indicates that only the 1st anchor text matters. This might also indicate the selection / extraction process mentioned in #2.

That all being said, I think I agree with Matt Cutts on this one. This is such a small issue that you really should focus on bigger picture stuff. It is interesting, yes, but not particularly useful.

I hope that helps!

I believe you can geotarget subfolders inside GSC, but you will need to set up each subfolder as a separate site inside GSC. Google has some tips here that might be of help. I would also consider using meta language tags as well.

The alt text ought to describe the image. Stuffing keywords into the alt-text is unlikely to have any kind of meaningful impact on your rankings.