Hearthpwn

I'd suggest going on hsreplay and/or viewing some YT clips of a deck you're interested in. I used to love to play Rogue but the only good current builds (that is if you don't want building a deck yourself which may be tough since you've not been keeping up with the meta) are pretty boring to me. In general, I'd say it's up to preference whether you like aggro/tempo/combo decks. I'd say it's more important than class since there are fewer competitive archetypes for each class than in the past (my opinion only)

That being said - rotation is coming so the meta will probably shift

Stormwind

*flies away*

The warlock imp package is getting nerfed for sure (probably the draw, either to 3 or 4 mana, likely 3).

The solution to Denatrius is prety easy, just remove the lifesteal tag from him and change cost to 9 mana. Druid won't be able to pull him out of his deck every time (unless they remove all >9 mana cards, which they do use now) and Denatrius becomes ONLY a finisher. For classes like Shaman that lack a good heal, that card is not gonna be as exciting.

Oh, also - I know the WR on Rogue is very low, but boy did they manage to make Rogue annoying again. It's not even about losing, it's about waiting forever for them to complete their turn. And I am a Rogue main so that should give you a perspective.