You would not type "After heating up the [sub-list ingredients]; mix them thoroughly."; you would instead separate the clause with a comma. The same ought to apply to lists of toponyms separated each by semicolon instead of comma. That said, "<city>, GA, I .." looks a little awkward (though less wrong than using a semicolon instead ...
Adding ", but" seems redundant. As a British Grammar user, I am familiar with this term and use it often myself, and simply "she tried, to no avail" will always suffice; slowing it down and jamming it up with the obvious ", but" is a little pedantic.
I would write it
He repeated the experiment in exactly the same way yet, then somehow, expecting different results.
Yet and then somehow are both conjunctions, and an alternative is offered so it is the same as
"I'm not sure what is in there. They are probably spanners or, and as well as, screwdrivers."
As @ Andrew Leach has pointed out, the meaning of the sentence is not entirely clear.
One solution is to hyphenate two words:
I can smell her obviously newly-ironed hair.
Another solution is to hyphenate three words:
I can smell her obviously-newly-ironed hair.
Granted, this doubly-hyphenated word is unusual and probably used rarely. A more natural-...
Edwin's suggestion is good, but it needs the serial comma to be clearly parsed as four: "Viroj, his wife Pranom, Joan, and I ..."
The "spousal appositive" commas can be safely dropped (regardless of any additional wives). Garner offers flexibility:
“This is not a hard-and-fast rule, and many publications ignore commas
with a name as a ...
So, I would strongly but respectfully contest the assertion that punctuation supervenes on spoken intonation. This is a rule of thumb and not a foolproof method for producing the correct punctuation, used by people who don't know the rules but want to do better than just random guessing (hence its advocacy by teachers). There are in fact rules for comma ...