Does it matter to split balance across addresses when minting ? Say I have 1million in one single address and I mint with it, if I solve a block I will lose the entire coin age of the address ? If it matters, what is the optimal coins per address ?
Minting happens per transaction. If you received 1 million coins in a single transaction, then yes, that would happen unless you kept some as part of your reserve balance.
Most people’s wallet balance is a result of multiple individual transactions. Each stake you put up is based on a single transaction of coins that were sent to you.
Quite tricky thing is, that the reward is rounded to cents. So if you have 1,000,000 PPC in incoming transactions of 1 PPC, you will get many times reward of 0.00 PPC and only after 365 days, you will start getting 0.01 PPC as a reward for individual 1 PPC blocks. Like this, you can lose almost all your coinage and not get the reward. If you have many small stakes, it might be a good idea to send all your balance to yourself to consolidate your stakes. (Assuming the reward is higher than the transaction fee to do that.)