Does it matter if all your coins are in 1 address or a bunch of lil stashes. Does it affect payouts?
Right now it doesn't matter much, but as the network grows and more coins are actively staking, the size of the blocks your staking will matter. Overall though, having smaller blocks will only mean that you stake less often, but your payout will be what it should be, IE, at least 5%, larger depending on the amount of coins actively staking.
For optimal staking, I would focus on having all your coins in one address, this way you are likely to stake more often and compounding can have greater effect.