not sure what the old fashioned way is, but the scrapebox expired domain finder does everything in 1 go. Put in your seed urls, and let it crawl and it will find all the expired domains, can filter them on the fly per your settings and then it checks metrics of the domains when done and gives it to you in a nice export. Also it has a wayback downloader in case you want to download and recreate the expired domain.
2 - here is a keyword video but I have a few others on there I think as well
3 - there are multiple ways to build links with scrapebox, you can use fast poster is the main one. A video series on how to do that
As for competitor research and site audits, there are lots of tools in scrapebox, but kind of depends on how you define those terms specifically
The video series above has a starter video on proxies, its the first one but you can search the channel I have all kinds of proxy videos including how to add your own sources:
5 - probably this will come as you put more of your other points together. Basically go as far as you can see and then you will be able to see to go further.