Yes you can install and use it (I hold my passes, tickets and loyalty cards in there), BUT payments won't work for now because Google says malware-ridden Oreo handset is safe and secure, but phone without ad delivery network running in the privileged mode isn't.

There are alternatives for payments (scroll the thread, maybe look up on GOS discussion site).

No, unfortunately.

If you live in the EU then you can use curve pay which can tap to pay.

Why is no tap to pay significant enough to stop you from switching to a phone that is private and secure? You can just carry a card and tap—they're tiny.