With how many TLDs there are now, it's easy to find an unused domain name especially if you use your countries local tld.
For instance, you make the property less alienable so the "seller" in a transfer is still just as legally liable if the new "owner" gets in court somehow due to the new content at the domain.
Then people wouldn't sell it, that's the point. They may transfer it in an acquisition or name change and in those cases, such legal liability is redundant. If company A buys B then company B Is company A
Another example: for abandonment it's not the first person that sees it snatching it up. Instead say, the first 60 days after lapse, interested parties register in a pool and then one is randomly selected.
There's vastly superior ways to do this then relying on naive price signals
There’s no decentralized method to prevent scalping. Scalping can happen whether it’s first-come-first-serve or auction.