The majority of the transaction (71.14 BTC) came from the first address. Can anyone explain why that address was recorded seventy times in one transaction, instead of just once with the lump sum of 71.14 BTC?
Transactions always consume the output of a specific previous transaction. If all funds available to that first address arrived there through many small transactions, you would need a lot of inputs to consume it as well. Bitcoin only conceptually deals with "money coming from an address", in reality it always comes from a previous transaction.
Yes, and 16u5Tq1A5sQhGF3C1M9aMQvjXb25NyTsrZ was my input for Slush's pool.