The first two will never come in an expansion but rather a full retooling of HS (as in HS 2.0).
The rest aside from Tournament mode are certainly doable in an expansion.
More than anything I want Blizzard to surprise/shock me. Come up with something that I haven't thought of or seen before that isn't based on some RNG clown fiesta mechanic.
The arena changes shouldn't be related to an expansion. Different team working on balancing that aspect.
http://us.battle.net/hearthstone/en...coming-arena-changes-with-dean-ayala-9-8-2016