I've read through HD wallet from various resources and have got the basic understanding about it, but am still confused by a few details
1) Each non-hardened public keys (thus addresses) can receive certain amount of Bitcoins. How's my total UTXO calculated? Is is simply the sum of all UTXO or there's some other mechanism automatically pool all these UTXO into somewhere
2) Kinda depending on the answer of 1), how does it work to send Bitcoin to some else in the case of HD wallet? If all public addresses have their own UTXO, then the wallet has to choose a number of UTXO as inputs for each new transactions. Is it how it works?
3) Do we use master private key to sign every transaction?
Thank you for your help