1) ??? no idea too
2) Click any transfer, Properties tab (the one with black bars). On the right there's 'N.nnn Available Copies', similar to uTorrent. If you are a seeder (=1.0 or 100%) then the value will be (1 + SUM_OF_SWARM), bigger than one. Or in other words as a formula =YOU_PERCENT + SUM_OF_SWARM_PERCENT. If not checked, it will only be = SUM_OF_SWARM_PERCENT
So you can see here at a glance whether all peers in a swarm have the complete torrent (>1.0 without counting yourself) or not (<1.0)
3) For each transfer there's the Peers tab. This setting controls additional info icons next to IP addresses, I think this is duplicating the information from the 'Status' column there (give or take)
4) This is the same as in Public Key Cryptography. The channel owner owns a special password called 'Secret Key'. This 'password' gives access to owner-only control features of the channel. Channels > Select a channel > Options. If you are the owner of that channel it will say 'Secret key OK'
5) "starting task affected targets" -> Start actions that were defined within that task. Many parts of the scheduler are currently untranslatable
this seems to be a bug, see https://forum.tixati.com/support/7078