From a security perspective, as long as you check the hash against Microsoft's website then it should be okay. Otherwise I'm not sure where to get Windows on ARM ISO's from.
Exactly. Thanks to raspberry pis and other ARM SBCs there's been a lot of ARM native support on Linux. Windows really hurt themselves with their initial ARM support.
Windows already works on ARM, but some X86 programs are still a little slow. The Snapdragons previously used weren't as fast as the Apple silicon too, so that didn't help. The original Surface X did have a lot more problems, but Surface 9 on ARM from all reports works well.