Your understanding is largely correct. I'll nitpick a few points for clarity, but overall I would say you have a decent grasp of whats going on here.
I can send the X BTC I purchased to my hardware wallet by giving the public key to my hardware wallet and specifying perhaps .99X BTC go to that wallet and the remaining .01 BTC is left as the transaction fee.
can A say "I paid B with btc amount 1.55821903" in any ways?
A used a 1.55824169 BTC "coin" but sent themselves change in the form of a 1.55200322 BTC "coin". B only ever received a 0.00621581 BTC "coin" and nothing else. B never had any control over the amount of change.
At no time did B have any control over the ...
2 thoughts on your understandings,
custodial sites such as Coinbase use a pre-configured transaction fee, when using the Ledger it will probably give you a few options to choose from (i've never used a Ledger).
there are multiple public address types (P2PKH, P2SH, and bech32 - see invoice address link below), and not all exchanges support all types.
How to avoid paying high fees or use bitcoin in a better way:
Use bech32 addresses starting with bc1
Use RBF for all transactions
Use batching whenever possible
Consolidate UTXOs with 1-5 sat/vByte if you have lot of small inputs in wallet
Use open source wallets with active development: https://bitcoinwallet.guide
Check mempool and fee estimates on ...
Fortunately you have many options.
The bitcoin core client allows key import with importprivkey
Adds a private key to your wallet. Requires a new wallet backup.
Hint: use importmulti to import more than one private key.
Note: This call can take over an hour to complete if rescan is true, during that time, other rpc calls may report that the imported key ...
Uneconomical UTXO requested [type: 1 (limit 6831), txOut.val: 5897, required: 98140
The output was 5,897 satoshis, but based on the addresses script type (1) the estimated fee incurred by spending this input (based on input_estimated_vsize*feeRate) would be 6,831 satoshsi. At this coin selection step, it was trying to find a coin that would fulfill 98,140 ...
This error message seems to indicate that one of the Unspent Transaction Outputs (UTXO) in your wallet has a lower value than the cost of spending it.
In Bitcoin, funds are tracked in the form of distinct transaction outputs. Each time someone gets paid, at least one new transaction output is created. While your wallet may show your funds as a balance, under ...