I'm implementing the bitcoin sending API using blockchain.info for my website and have a couple questions.
Let's start with address A with an input of 10 BTC. I use API and pay Alice for 9BTC.
Q1: The 1 BTC will return to my change address and unusable until the transaction is confirmed, correct? Q2: How the change address is managed on blockchain.info? Q3: If I turn on HD functionality, the change address is the HD generated address?
My plan is to use the input until it's almost run out, and then manually top-up from cold wallet.
Q4: So the transaction I sent to Alice or anyone else will always have 1 input, and 2 inputs (when I top up from cold wallet), is this correct?