[squeek.]

• The startup errors can be ignored. They are mostly just caused by a client-side material proxy not being found on the server, which doesn't matter (the proxys are just used to render things on the client, the server does nothing with them)
  
• Omni-bot is intentionally not included with the release version of the game. It is unfinished. That error can be ignored.
  
• Game modes are map-dependent and defined by the map's Lua file.
  
• There are very few important server variables that relate to actual gameplay (other people could probably give more information about server optimization). mp_timelimit, mp_friendlyfire, and mp_prematch are probably the most important.
  
• The default map cycle included with FF should be pretty decent.
  
• 66 tickrate is optimal

Hope that helps.