At the link from today's post, https://x22report.com/omnipresident-part-3/ I see “elections until now has been” but I'd write “have been”. What I've learned, is “singular 3rd person > has, all others/plural > have”. What am I missing? Some exception, or developing and changing tradition?

You are correct that this example is an error, but let me add a little nuance. There are situations where a noun which looks plural and was originally formed as a plural takes on a sense where it can be used in the singular. "Marbles are fun to play with" but "Marbles is a fun game." The distinction arises when we stop using "marbles" to refer to a collection of objects (a handful of marbles) and instead to refer to a singular concept (a game of marbles).

In some cases, the singular concept completely supplants the plural. "News", for example, was once just a plural form of "new", referring to many new things, but now we always say "the news is bad", not "the news are bad". The same thing happened much more recently to "data": we almost universally say "data is", not "data are", even though the word was formed as the plural of "datum".

In your specific example, we could in theory start to use "elections" in the same kind of singular sense as "news" or "data", but this is not anything like common in today's actual usage. Readers are much more likely to interpret "elections is" as a simple error rather than a deliberate stylistic choice.

Countries/national states mentioned are often referred to as 'she' but the verb goes plural -- I take it they are either 'it' as inanimate themselves or 'they' as all- the-people-they-enclose. Some 'motherland' connection, …?

This is a difference between British and American English. In American English, when referring to a large organization such as a company or a country, you always use the singular. America is, Amazon is, etc. But in British English, you might use either "is" or "are" depending on your specific use case. If you're referring to the organization as an organization, you would still use the singular, but if you're referring to the group of people underlying that organization then you'd use the plural: "British Telecom is a huge company" but "British Telecom are unhappy about their pay cuts."

I sometimes see sentences where 'be' is missing to my eye. (Sorry, can not find an example among latest posts right now). Again: as a rule of thumb, words and expressions shorten with time: syllables in words and words without which thought remains understandable, just drop off. Am I observing this process, or just unkempt postings?

The phenomenon you're referring to is called ellipsis, but I'd need a specific example to say whether you're seeing ellipsis, or simple error, or some other phenomenon such as headline grammar.