DUI is only a misdemeanor in most situations. Speeding is usually just a traffic infraction, even at 20 over, unless they can also prove reckless driving (which is criminal, but also generally only misdemeanor criminal).

In CA, the fines double at 15mph. Anecdotes suggest they rarely even bother people going less than 15 over and often write tickets for more than 15 at the lower level anyways. They actually have a law that makes exceeding 100mph considered reckless driving.

Then we get further away into NV, UT, ID, MT, they have higher speed limits (75 and 80) to begin with. NV, speeding is a misdemeanor (fine no more than $20 per mph over the limit capped at $1000 which implies misdemeanor charges for going 50 over!). UT's reckless driving law kicks in at 105mph. ID doesn't have anything super clear on the subject, but there doesn't appear to be any explicit excessive speeding statute. Similar in MT, though school and work zones can upgrade the infraction to a misdemeanor. No mention of felonies in any of those states...

I think you have some incorrect perceptions on how things work in other states.

The box is usually "have you been convicted of a crime?" on a standard application. I don't think any ban the box laws prevent an employer from doing a full background check once the person has an offer, especially if the role is deemed sensitive in any way.

Honestly, if this person is worried about it, and especially with the visa complication, it may be worth at least having a consultation with an employment lawyer.

Yes, at-will means they don't have to have a reason to fire an employee. But the employer still has to follow their own rules and procedures, and there are lots of protected reasons why they can't fire someone. An employer as large as Microsoft is going to have extensive and comprehensive policies.

This is a question for a professional though, not something you're going to get reliable help from reddit on.

If you're living in the Airbnb for 3 months, that very well could be your residence. Update your address with a bank and your employer, and you'll have evidence for an enhanced license too. Yeah, changing your address twice sucks, but there's no minimum stay requirement. It's about intent -- and intent not to return to where you came from.