At the moment, I use the BTC.com API to get more data from bitcoin. The number of transactions per BlockChainData Dataset in the Wolfram Language is capped and the process to get more is either slow or more complex than using the BTC API.
If Wolfram Research is using the same API, the total number of transactions can be retrieved with the "total_count". If the total number of transactions is off, then so is the total balance.
Bitcoin stores transaction date-times as UnixTime in UTC (GMT-0). Some times in the current BlockchainTransactionData seems off by one hour (as of writing, Nov 2022).
The date conversion in BlockchainTransactonData uses the user's current timezone, not the prevailing timezone offset that corresponds to the historic date.
When I use the BTC API, I convert them with this function I found with the help of this Community:
DateConvert[ux_Integer] :=
FromUnixTime[ux,
TimeZone ->
TimeZoneOffset["America/Chicago", "GMT", FromUnixTime[ux]]]
Now all date-times are the same as reported by BTC Explorer.