Away messages do not (except on DALnet)
Idle times do not
Channel topics do not (except on DALnet)
A note on +k (key) propagation. Dueling keys do not propagate. If the channel has one key and during a split, someone creates another key, when the net rejoins half the net will have one key and the other half will have the other. This will continue until one person sets a key on the channel overriding both existing keys. (No, I have never personally tested to see how many keys I could stack on a channel.)