No, the hit and target (it is called like in Nxt) requires only hashing. But as implemented the harvesting account is always generating a block (even when the node is not publishing the block) and that of course requires signing.
What task is solved by generating a block even if it's not published? If there are 2 accounts on a node, one of them contributes less into security of the blockchain and it's a waste of CPU cycles to use it for signing unless you have something special.
1) we were discussing your attack scenario
2) I've explained that unlike in NXT, you'd have to generate block for every "delegated" account that attacker owns
3) I gave you the number that's sensible for an attacker to handle
How is your question related?ok I think I know what you had in mind - yes it'd be possible to decide who's gonna score best block from those attacker's 10000 accounts upfront.
