Are these carfax items red flags when buying used car from a dealer?

A glass repair could be something as simple as a stone thrown up, which smashed the windshield. Not really an issue.

Failed a safety inspection after only three years suggests a serious lack of either care or maintenance. Sold at auction suggests they then wanted rid of it.

The glass could be trivial. I broke a windshield accidentally in my driveway.

What state?

In some US states the inspection is every year, in others the inspection is only when there is a title transfer. You can fail for a cracked windshield, or a fogged headlight, or lack of tread on a tire. Sometimes the cost to fix the failed item is only a few bucks. But the failure is still noted in the report.

What certification is the dealer giving? Some claim they do a very comprehensive inspection and prep.

Some people want their own mechanic to inspect the car. See if the dealer will allow it.

Treat it like any other used car. Bring it to your own mechanic, and pay them to "check it out as if your kid was considering buying it." Then factor their report of what needs service now, or what will need service soon, into what this particular vehicle is worth to you and negotiate on that basis.

Last time I did this, the mechanic charged me $200 for the service. But that was almost 20 years ago, and cost has presumably gone up since then.

If simply getting it checked out would raise the total cost beyond what you're willing to pay, walk away and buy something else. If the dealer refuses to let you do this independent evaluation, walk away and buy something else.