There is a good little addon called Jerk Tracker. This is what is does:

Quick Description:
All of us have been on a server at some time or another when an admin isn't around and this jerk decides to go ballistic on his team by attacking them with nades, flashbangs, knifing, etc. Jerk_Tracker allows admins to configure each offense and that offense's punishment separately using a minimum/maximum setting.
Protects Against:
1. Friendly Fire
2. Spawn Attacking
3. Spawn Flashing

(spawn protection time configurable by the admin)
(each offense configurable per ROUND and per MAP)
(punishments configurable per offense)
If we used this along with Mani's options then FF on should be fine. There are also lots of announcements to warn people:

If you choose to have announcements turned on, Jerk Tracker toggles through 3 different messages at each round's start. Each round, one of the following 3 messages will be displayed at random:

1. [Jerk Tracker]: Do not retaliate for team-wounding - you may be kicked/banned of you do.
2. This server is being Monitered and Administrated by Jerk_Tracker v1.4
3. [Jerk Tracker]: You may be kicked or banned for attacking teammates in any way.
There are tonnes of variables in this addon, so everything can be fully customised.