Txn fees get destroyed in Peercoin, the minter only gets the coinstake.
As for the work flow, let’s go over bitcoin again real quick. I’ll use the word ‘miner’ when I’m talking about PoW and ‘minter’ when I’m talking about PoS. So every miner is gathering up a bunch of txns and forming them into a block along with a random number. If the resulting hash has enough zeros at the beginning of it, determined by the difficulty, then it is considered a ‘valid block’. If it doesn’t, it is rejected and the miner changes the random number and tries again.
In PoS, the random number is instead the time. So every second the minter gets to try again, but no more than once per second. Because this calculation takes much less than a second to do on any normal computer, they are not limited very much by hardware. This allows Peercoin to be much more efficient and for minters to build and broadcast blocks from computers as basic as a raspberry pi. Because it is so easy to do, minters feel trivial cost when they add txns to the block, so they can easily add as many txns as they can find even though they get no fee reward for doing so (other than the slight decrease in supply).