Mulligans
Aggro Mulligans
Accept that you won't be able to save cards for the Combo or ramp early and focus on keeping the board clear (especially against pirate warrior)
Control Mulligans
Keep Nourish only if you have Wild Growth or you're confident you're going up against a slow/combo deck such as Jade or Handlock
I know the season is coming to a close and this will be stuck in wild format. I just wanted to share my final rendition. I was able to comfortably hit rank 5 in this the last few seasons.
Obviously you’re looking for the combo: Aviana + Kun the Forgotten King + Malygos.
You really should try to avoid playing Barnes on curve. However, if you have an innervate and you haven’t drawn: Aviana, Gadgetzan Auctioneer, Emperor Thaurissan, Malygos or Bloodmage Thalnos then you can have some interesting plays. This does possibly telegraph your deck (since Jade is the assumption) if they see a card like Kun the Forgotten King or Malygos.
The craziest turn 5 I had was: Barnes into Aviana with Gadgetzan Auctioneer in hand followed by Innervate . You can imagine what happened from there.