As far as I know, only information about outputs is blinded; everything else is open for a coordinator to analyze. A CoinJoin coordinator verifies if provided inputs meet certain criteria, particularly, it checks if inputs haven't been double spent in the same round, haven't been spent before a round started, and that they have a sufficient number of confirmations (for coinbase outputs it must be more than 100, for others I think a single confirmation is enough), and more importantly, it checks whether those inputs contain a sufficient amount of coins to participate in a CoinJoin round. Without this special check, it would be a tough task to construct a transaction because (1) these transactions require equal amounts in the first place, and (2) the amounts should be sufficient to cover mining fees and coordinator fees. Also, the cost of attacking CoinJoin rounds would be very low - a nefarious actor could indefinitely interrupt mixing rounds by spending tiny amounts. So, I don't think blinding inputs would work out, at least not in an adversarial environment where no one trusts his neighbor.

I have no idea, either, but the Trezor team has confirmed on their Twitter that they are working on a CoinJoin implementation: https://nitter.net/Trezor/status/1566708740597972997, and Wasabi Wallet team is excited about "hardware wallet coinjoins."