General questions
Account registration is not requried to mine. We simply use the payout address that you specify when starting the miner...
nexus_cpuminer.exe nexusminingpool.com 9549 [yourpayoutaddress] [threads]
Yes the pool charges a 1% fee to miners. This is subsracted from the block amount and is included in the Coinbase of every block mined by the pool (viewable on the public blockchain using an explorer)
NO! Unfortunately the transaction information for mined blocks displayed by the wallet/rpc commands does not currently include the miners address. This makes it impossible for the exchange to work out which account to pay the balance to. This is planned to be recitifed in a future version of the Nexus wallet.
Earnings & Payments
Each miner searches for and submits solutions to the current block. These are then converted to shares in the block rewared based on the difficulty of the share submitted.
The more shares you submit, and the more difficult those shares were to find, the more you earn.
The balance is how much you have earned since the last time you were paid. When your balance is large enough the pool will include some/all of your outstanding balance in the next block the pool mines. The amount you are going to be paid in that block is what is shown in the Payout amount.
This is a result of the last block found being an orphan. When the pool finds a block the current mining "round" ends and the shares that all miners have found are used to work out how much each miner has earned during that round. At this point your balance goes up by that amount and a new round is started (all share counts reset to 0). The pool then has to wait a little while before it knows whether the block it submitted has been orphaned by the network or not. If we find it was orphaned then we essentially reopen the previous round, reinstating the shares everyone submitted, reducing the balance of all miners back to their previous amount, and refunding the balances of those miners who were paid in that block. So this is where you see the balance go back down to it's previous amount.
Miners payments are made in every block that is mined by the pool. However, due to the variable block size, not all miners can be paid with each block. Instead the pool attempts to "fill" the current block reward with as many payments as possible. We prioritise payments based on balance, paying the highest balances first and working down. Therefore it can take some time to pay out balances for small miners, so please be patient.