Yes, they’ve done it for me in the past.

You must contact the seller and ask him to transfer the license to your steinberg account.

No

If the software wasn’t explicitly mentioned in the used item for sale ad, then don’t expect you’re getting it. Just because the product originally came bundled with the software doesn’t mean the current seller is offering it for sale with the hardware you’re buying.

You could, they will most likely ghost you.

Officially, the seller must ensure that the scope of delivery is complete.

However, contact support and provide them with the invoice (or other suitable proof of purchase) and you will receive the codes.

If you use e-mail support, please note that Cubase 13 has recently been released. The response may take 1-2 weeks. They have an in-house support team. Competent, but quickly overwhelmed.