I don't like it at all. The layout is confusing and looks very unprofessional. I can't quickly get to the new articles.  Let's just go back to the old style which was good for a very long time!

---> The one thing that I have still not happened on are the Ancestry, Findmypast, and Family Search spotlights.

Go to the search box that is on most pages on this site (it says "Search Entire Website") and enter whatever it is that you are looking for such as Ancestry, Findmypast, or FamilySearch. That will show ALL articles that mention whatever you searched for.

---> I don't see a way to change back to weekly.

At the bottom of every daily email message you receive, there is a link labeled UNSUBSCRIBE. Click on that and you will not receive any more daily email messages but will continue to receive the weekly email messages.

There is also an UNSUBSCRIBE link on the weekly message also in case you wish to not receive those.

--->  It said I wasn't a subscribed member.  I tried logging out and re-logging in and I still got the same message. 

You are indeed a Plus Edition member. Did you log back in using the correct email address and password? (Some people have 2 or more mail addresses and will sometimes use the "other" email address.)

Next, after logging in, you DID click on "Latest News - Plus Edition", right?

---> However, the search functionality doesn't seem to retrieve information previous to the new site.

That is mostly correct with a few exceptions. 

The articles in the old site software are in a radically different format from the new site so there is no automated method of copying from the old to the new. Instead, I am manually cutting-and-pasting articles as time allows. I copied several this past weekend.

HOWEVER, I am finding that many of the old articles are either out-of-date or no longer relevant. For instance, an article I posed in 2006 describing the planned agenda for an "upcoming" genealogy conference to be held in 2007doesn't have much value now. I am not copying messages about "future" events that occurred years ago.

Also, an amazing number of articles are for out-of-date products, URLs that have changed, companies that are no longer in business, and so on. I will not be copying those. Also, checking URLs and finding updated addresses is often a very slow process so the process of manually posting articles will require months to complete.