Heh - those all sound perfectly natural to me except ‘architecting’, and I majored in architecture. To be fair, ‘leveraged’ to me is a very specific economic term, and I’ve only ever heard ‘mothballed’ in the context of city-builder games (used to indicate a temporary shutdown of a building or industry). And, as noted, gifted is pretty much strictly written.
I suspect that this is exactly where the usage came from- after all, if I can re-gift that ugly picture frame to my sister-in-law, someone must have gifted it to me. I wonder when we’ll start seeing “purpose” as a verb.
Newspaper headlines and captions are notorious for either slightly abusing words or using words that you might not always use in real conversations. “Gifted” is much shorter than “gave as a gift” and yet carries the full meaning to the reader. When everything you write has to fit within a certain number of column-inches, you take shortcuts where you can.
I do sometimes use “gifted” in conversation, but I’m at least partly influenced by all the tax law I read.
There’s nothing particularly American about turning nouns into verbs. It occurs in British English just as much.
I did not intend that as a criticism of American English. You might say that American English speakers are quicker to adopt new forms than British English speakers. It certainly does happen in British English, but I’m not sure that it happens “just as much”. I think we import a lot of these new verbal forms from America. The likes of “leveraged” and “architected” are American in origin.
I’m pretty sure I remember Strunk&White being against the usage of gift as a verb.
Since I think it’s probably the best English “style” guide I would consider “gifted” (as a verb) to be sloppy.
I can’t find my battered copy to verify, I should probably get a new one. Great book, if only for the most genius example of why writing style matters:
“Soulwise, these are trying times.”
The original quote is left as an exercise for the reader 
I didn’t take it as a criticism of American English. I don’t know of any evidence that American English is more accepting of turning nouns into verbs than British English is.
There are those who think that Strunk and White is a terrible style guide:
That criticism seems more to be complaining that it’s a terrible grammar guide. I wouldn’t say it’s terrible, just not very good for grammar.
The context in when Strunk first would have written the thing matters - he was writing for undergrads in the first half of the 20th century. Back then one could probably assume that any college undergrad had had the rules of english grammar hammered hard into her in her K-12 education. So a “grammar” book would probably not be needed, a style guide would.
Things have changed - I didn’t get a proper formalized grammar lesson until I was in 11th grade. Teaching styles have changed. The only grammar I got up until then was an admonition when I had seriously broken a grammar rule, and I sort of pieced together what little I know of grammar from that and a lot of reading.
So a criticism of the book as a poor grammar guide is entirely valid but it misses the main goal of the book, which is as a style guide.
But now I’m way off the OP, so I’ll drop it. I can understand criticism of Elements, but I still think it’s a valuable read.
:smack: No it’s the sort of careless error I predicted after saying I was an EFL teacher, see line 2 of my OP
Many thanks to all who have replied - in Europe we can fall into a trap of hearing “media” or “business” English from American sources and assume that they are more widespread or welcomed than they actually are and it’s good for me to get the fuller picture. The legal aspect is also very useful.
Actually no Ximenean, I just wanted to know when a person would say “gift” rather than “give” 
Mind you I am fascinated as to why we’re busy verbing some nouns yet abandon other ones as old fashioned eg I lunched with John versus I had lunch with John
I’m glad to see others suggest it may be an erroneous back-formation from re-gift as the thought had occurred to me.
Oh and Reply? For addicting I heard the word used on radio and questioned it, my female twenty-something bay area Californian cousin gave the explanation on the spot. I have had her idea independently confirmed by another female twenty-something Californian from LA who was in Europe training to be a teacher. Now to be fair I’ve also had twenty-something Americans from elsewhere in the States who share your opinion so the jury’s still out.
MW11 begs to disagree with you, at least about the neologism part:
All English speakers brazenly use nouns as verbs, every day, without batting an eyelid. Paint a room, heat your dinner, butter some bread, book a ticket, paper over the cracks, skin an animal, knife someone in the heart, table a motion, sum the series, influence a decision, etc., etc., etc.
Those demned Tewdwrs! Alway tampering with Ye Olde English Language. forsooth! 
It’s a seperate meaning. When Sean Penn was presented with the Best Actor Oscar, it wasn’t being gifted to him by Michael Douglas.