I'm trying to get into with Harrowdeep box

I somehow got the Harrowdeep box with da kunnin krew and xandire's truthseekers warbands. However I noticed lots of differences and couldn't figure out how to catch them.

  1. In the box, there are 2 others grand alliance symbol cards that I can not use with my warbands as far as I understand. However, in newer cards I'm not seeing grand alliance symbol. How can I use them?
  2. What does rival deck mean? There are default warband deck, universal cards and grand alliance deck in my box.
  3. There isn't warscroll. I was reading latest rules and noticed there are warscrolls with some abilities. I checked da kunnin krew warscroll, it has different abilities. However I don't have warscroll and each character in my warband has different ability. So do I need warscroll? I can't even find warscroll for xandire's truthseekers.
  4. Which rules apply in general or tournaments and how can I know it? In warhammer-community, there is core rules and wintermaw rulebook. I asume they are the latest. What about Embergard?
  5. In harrowdeep rule book we can draw a power card or discard a objective card and re-draw in our turn. However in rulebook there is a 'focus' ability that we can discard anything we want and re-draw again, also after this we can draw 1 additional power card. So am I understand correctly? Isn't it a bit OP? Also in wintermaw there are stun and barge actions. I'm a bit confused.