Agreed partially.
6. Partially. Depending on the strategy it might be interesting to have KYC. After all #monero is a boat accident waiting to happen. 
10. The problem with the cold wallets I tried, is that you can’t prove payments since you can access the transactions key, so careful here. 

 Yep ledger has all your transactions. If sparrow works with a ledger, then is there a 3rd party wallet for the ledger hw monero app?  

 It works fine with the monero-cli and I guess also with the monero-gui. One solution is to transfer first out of the hw. In any case I’m not a great fan of the hardware wallets for #monero