Can airport immigration in Thailand see the full travel history from previous passports?

Of course they can

There are more and more reports that the Immigration Bureau has more and more focus on bogus ED visas. The school must be an officially recognized institution. An application for Elite Visa will be denied if having such a bogus EB visa in the past. They are checking it very carefully. About your passport, it doesn't help to get a new one IF you show up on the screen as someone with a past bogus visa, BUT the main focus at the border station is your present passport. So yes and no, sometimes it helps to get a new passport, sometimes not.

Of course. Just the same as USA immigration can see your history.

There is this thing they have called computers 😳

Were they bogus ED visas? If they're genuine and you have proof of study, you won't have a problem

Yes, they can. Your biometrics (picture and fingerprints) will reveal your entire travel history (irrespective of your passport shown). Having said that, I still feel like a new / blank passport rises less suspicion than one covered in many / mostly Thai stamps. A suspicious passport more likely leads to a deeper dive into their computer.

Yes they can see your full history

There's a reason they take your photo and fingerprints every time.