Here’s my take:
The domain aftermarket has a big problem… it exists. This market shouldn’t ever be allowed to exist in the first place. ICANN should’ve blocked this bullshit a long time ago and forced registrars to just let domains expire and free the space. Also add a few provisions about unused domain names and about selling them.
The free transfer would be hard to enforce.
I think it could be accomplished. If any income from the sale or transfer of a domain, above the standard registration fees, is taxed at 100% that would stop most, especially businesses. No it wouldn’t be perfect, but no tax system is.
ICANN doesn’t have the authority to levy a tax. I’m not sure how you would enforce a system like that.