Along with Patrick's great ideas, take a look at Wikipedia and DMOZ (Open Directory Project). Is the old company listed in either of those? Sometimes signals from those sites can be very strong.

Yes, once you get back into doing it everything will come back to you quickly. Have fun!

Wait till Google crawls your page again. You will know when this is by checking the date on the cached version of the page, which you can find by doing a search for the URL of the page you are interested in, then clicking on the little green down arrow next to the URL in the search result.

You request an update in DMOZ, explaining about the change. They are much quicker at updating an entry than at adding a new one. (I know, because I had to do an update myself.) There is also a handy meta tag you can use on your site, , which tells robots not to use Open Directory information.

For Wikipedia, if you know a friendly editor you can ask them to make the change, or else you can request an edit on the company talk page.

And of course DMOZ, if you are talking old-school directory. And the keyword meta tag (not exactly a tool, but it got the job done).

I keep our privacy policy indexed. I figure that if someone is thinking about interacting with us in some way and doesn't happen to notice the link in the footer or the call-to-action boxes, it should be findable in search so that we don't look like we are hiding something. And for the second part of your question, I think having your privacy policy readily accessible helps users feel more secure and that is a good thing, so I would still have it in the footer.

If a page has no links and has not been submitted another way, Google won't see it.

The title tag is what Google often shows in the search results. And external websites, especially social, often use title tags as anchor text for links. So even though you don't see it at the top of the page in mobile, it is an important element.

Yes, dmoz is still accepting listings. It is a large, human-edited directory and submissions can take a very long time to process, depending on your area. They also don't accept all sites. As far as value, it is certainly not the golden ticket it once was and the general consensus probably is that it has little or no impact. That being said, it's not that difficult to submit a site and it wouldn't hurt to be accepted.