So, in your example, you are using a 302 redirect which is temporary, compared to the permanent 301 redirects. Depending on Google, they can either keep or drop your first 302 redirect "link 1" at any time. It's unclear how long they last for.
1.Will Google replace link 1 with link 3 in its index after a while? Or not because the first redirect Google sees is a 302 before a 301 - And if not, how can we replace it?
Ok so your link 1 is a temporary 302 redirect, assuming it was the absolute original link for that page to another redirect of 302 (link 2) and finally to your intended page.
Google will eventually replace link 1 in its index IF you do not have any other internal links pointing to it or within your sitemap. Meaning you need to remove the usage of that link in order for Google to quickly remove it from its index.
The best way to know when Google has removed your old URLs and only indexed your targeted URLs (link 3) is to use the search operator. It would go like this "site:www.yourdomain.com/[link 3]", if you do this and see all three links are still there, you'll need to wait a bit longer. To help out, check through your sites links and see which pages are still linking to link 1 or 2.
Finally, when only link 3 is appearing on Google, you're good to go. If you have backlinks to link 1, I suggest making it a 301 permanent redirects to link 2.
2.Does link 1 pass the Pagerank of link 3? Or not because the first redirect Google sees is a 302 before a 301
Technically it will, however it will dissipate the power of the PageRank similar to normal internal linking's rate. That means for each redirect you'll lose, let's say, about 5-10% PageRank "power". This is not a confirmed number, just an example. Here's what Google employees had to say about that:
“I mentioned that a certain amount of PageRank also dissipates through 301s. …The amount of PageRank that dissipates through a 301 is almost exactly, is currently identical to the amount of PageRank that dissipates through a link.”
No. A redirect chain is a somewhat "infinite" loop of redirects that keep pointing back to a source the triggers the chain again. For example, if you accidently added a 301 redirect from link 3 back to link 1, it will cause the chain to happen and never really load a page. That is VERY bad...
This is simple multiple 301 redirects. And a best practice in SEO is to ensure your website is easy for Google to get to the final page without any problems. So, like I said above, keep checking on your URLs through that search operator, Google Analytics or Search Console, and even a tool like Ahrefs to see if your link 3 is generating more of the traffic than the other pages.
Also, I would suggest setting up a canonical tag for each page to ensure you don't get duplicate content warnings from 3 pages:
So, in your example, you are using a 302 redirect which is temporary, compared to the permanent 301 redirects. Depending on Google, they can either keep or drop your first 302 redirect "link 1" at any time. It's unclear how long they last for.
1.Will Google replace link 1 with link 3 in its index after a while? Or not because the first redirect Google sees is a 302 before a 301 - And if not, how can we replace it?
Ok so your link 1 is a temporary 302 redirect, assuming it was the absolute original link for that page to another redirect of 302 (link 2) and finally to your intended page.
Google will eventually replace link 1 in its index IF you do not have any other internal links pointing to it or within your sitemap. Meaning you need to remove the usage of that link in order for Google to quickly remove it from its index.
The best way to know when Google has removed your old URLs and only indexed your targeted URLs (link 3) is to use the search operator. It would go like this "site:www.yourdomain.com/[link 3]", if you do this and see all three links are still there, you'll need to wait a bit longer. To help out, check through your sites links and see which pages are still linking to link 1 or 2.
Finally, when only link 3 is appearing on Google, you're good to go. If you have backlinks to link 1, I suggest making it a 301 permanent redirects to link 2.
2.Does link 1 pass the Pagerank of link 3? Or not because the first redirect Google sees is a 302 before a 301
Technically it will, however it will dissipate the power of the PageRank similar to normal internal linking's rate. That means for each redirect you'll lose, let's say, about 5-10% PageRank "power". This is not a confirmed number, just an example. Here's what Google employees had to say about that:
“I mentioned that a certain amount of PageRank also dissipates through 301s. …The amount of PageRank that dissipates through a 301 is almost exactly, is currently identical to the amount of PageRank that dissipates through a link.”
No. A redirect chain is a somewhat "infinite" loop of redirects that keep pointing back to a source the triggers the chain again. For example, if you accidently added a 301 redirect from link 3 back to link 1, it will cause the chain to happen and never really load a page. That is VERY bad...
This is simple multiple 301 redirects. And a best practice in SEO is to ensure your website is easy for Google to get to the final page without any problems. So, like I said above, keep checking on your URLs through that search operator, Google Analytics or Search Console, and even a tool like Ahrefs to see if your link 3 is generating more of the traffic than the other pages.
Also, I would suggest setting up a canonical tag for each page to ensure you don't get duplicate content warnings from 3 pages:
Yes, it's perfectly normal for that to happen. Somewhere on your website, sitemap, or files could still be the actual URL to link 1 that Google keeps picking up from something.
As I mentioned above it's best practice to find any mention of Link 1 on your website and turn it into the Link 3 that you want to be the primary URL.
It does take some time for everything to clear up, so double check and remove any "live" references to link 1 and 2 on your website and switch them to 3. That's the most you can do at this point.