1) You can switch any skills out at anytime you are in combat. But as a "basis" people pick either PvP or PvE and show what they are doing -- typically PvP is thought to be higher importance. Typically one bar is SINGLE target PvP, and then the other can be buffs - or AOE - or Heals - or a switch from range to melee. In PvP you will find many differing situations. So you will become flexible as to exactly what you are facing. 2) Red = Dead. If you can see them you can kill them. Cyrodiil zone is very big and takes lots of traveling. Though apparently you can cross realm friends/guildies into the same dungeons. 3) Block is holding down right click, yes. I think Block is 35% for non-shield types and 55% for shield users. A few skills can increase this though... 1) Sword & Board +10/20%. 2) Always lower projectile damage 8/16% if blocking or not. 3) Draconic Power +5/10%. So you could have 85% and 101% vs Projectile.