Not forgetting, simply deferring discussion on that. We’ve a much
smaller limit to deal with right now. But even that limit would have to go
to remove this attack.
No,
with no blocksize limit, a spammer would would flood the network
with transactions until they ran out of money.
I think you are forgetting even if you remove the blocksize limit, there is
still a hard message size limit imposed by the p2p protocol. Block would
de-facto be limited to this
size.