The answer to most of these questions, given is Bitcoin’s design, is the same as: would I do this if I were a miner or writing mining software? I’m 95% certain miners put the highest fee txs in their block template as they come in. They’re doing the work anyway, why not maximize your returns? In PoW your likelihood of mining a block is independent of the last hash you made, so incrementing the nonce, replacing a tx, or replacing all txs before you hash the header again, all have the same odds of finding the block. Ie you don’t make progress as you mine, you merely exhaust a very very tiny few of possible losing blocks as you go - all that matters is you don’t choose the exact same block again. Eg if I flip a coin and it’s tails, the odds of it being tails on the next flip is still 50% regardless of whether I flip it tomorrow, or on the moon, or on a hill, or in a valley.