Well for the mulligan in general I tend to keep the 3/3 pirate, edwin (if my hand supports it) and backstab (vs decks with early minions) + what he says you should. since these cards have the higher winrates in the mulligan.

+2 Mark of the lotus
-1 hadronox
-1 Jade idol
seems like a good improvement.

Well Aya and patches are in other t1 decks, so they are good legendaries that work in many decks;
Jade druid, Evolve Shaman, Aggro rogue, Jade shaman, Jade Rogue, pirate warrior, Miracle rogue, aggro druid, zoo warlock.
very safe crafts.