Which is something you might do as an individual, but it's pretty obvious that bitcoin implementations aren't going to hardcode every single miner into the peerlist of every single node. So realistically, whether you have a spammy workaround or not, the implementation that most nodes run matters and the filters still matter.

No they don't. If someone wants a transaction to be mined and it is valid, it will be done. That is the whole way the fee market works.