I have tweaked the hardcore server settings as below.

1) as pointed out by snipe last night, respawn time was at 10 seconds. It seems that patch 1.5 altered the meaning of "0". This used to mean zero, and now means "use default" for certain options, respawn time being one of them.
Therefore I have set the time @ 7.5 seconds for sabotage and 3 seconds for all other gametypes.

I have also enables friendly fire. This should work as follows, but is untested.

kill 1 to 5 team-mates = 5 point loss per kill (and a load of abuse )
kill over 5 team-mates = damage reflects back to you and you get 20 second respawn delay.

The point of this is to reduce spam nading and airstrikes, but ensure we don't attract rampant team killers.