Re: Go back to text based email
I doubt it in both cases. It's quite easy to see the from address in pretty much every email client. People who don't choose to look at it can ignore it just as well when it's in the longish blob of server logs they don't understand as when it's the only thing in the from box.
As for URLs, people can easily see the URLs and we show them how. I'd agree with you if I thought the tiny extra step to view that information was the problem, but all the evidence I've seen suggests it's really not. For example, on the most recent phishing message I had to clean up from, the senders included a shortened URL* but, I suppose in case someone reported it which is what I did, they also included the destination URL in plain text which went to [random letters].digital/[more random letters]. Neither of these struck the user as suspicious and they cheerfully loaded the site. Seeing where they were going was not enough to stop them in that case, and those who pay enough attention to that to check the URL can also remember to hover over a link to see it.
* One other downside with making mail plain text is the boost to shortened URLs it's going to cause. Many sites are set up such that they have very long URLs. Pasting such things into mails when they'll wrap onto multiple lines will be ugly, so people are going to shorten them so it's less so. Some will make their own link shortener which still indicates where they're going, but many will not be competent enough to do this and will use whatever shows up first in the search results. When everyone does that, it will be a lot more annoying to find out where the average URL goes because, instead of hovering over the link, you have to figure out how to expand the short URL from whichever service was popular this week.