There are some privacy and tax benefits. But they are not really anonymous, so it's better not to think of them that way.
If you need a bank account at any point, you'll need an FEIN. Banks also do KYC. Lines of credit and such require personal information. Even if you don't need banking, executing contracts on behalf of the LLC requires an officer or similar to sign and identify themselves. Beyond all that, your registered agent is always a link back to you. There's no way around that if the court system ever gets involved.
1) Limited liability - not sure what liability I need protection from, but I imagine it could be valuable in the context of smart contracts (i.e. sale of goods or services, and if smart contracts develop further, potentially allowing me to join anonymous general partnerships with limited liability)
2) Tax benefits - option to elect to be taxed as a corporation if my coins rocket in value and I want to sell in less than a year
I can't comment on the smart contract aspect, but there are definitely tax benefits when it comes to trading, assuming you structure things correctly. If you're putting a lot of money and volume in, it's something to consider and discuss with a tax professional.
3) Choice of law - It looks like Wyoming has favorable legislation regarding utility tokens which I could avail myself to by setting up a Wyoming LLC
Wyoming law doesn't override federal securities law, so be careful.