Something you should always do is focus fire. If Ying has the Life Like Legendary Card, this is even more effective as the heal beam loses 30% of its healing ability, but if you spread out the damage, she will have 40% extra overall due to 2 beams.
Assuming Buck hits you at point blank with all his pellets in the head, he will need 3 shots to kill you.(2.8s) This will never happen. You can knock buck down to 500 HP with the Daggers+Pounce+Daggers combo (about 2s). Easy kill from there.
You do not want to duel Maeve as her combo WILL one shot you. Stay away from where she likes to play unless you have an ally who can kill Maeve first with you.
If you have pounce available don't be afraid to engage Talus. Hitting both daggers, pouncing and hiting both daggers again will finish off Talus before he can react.
If Meave isn't using Artful Dodger, and you have Surprise Attack, break hidden with Poison Bolts and do your hit her once from behind. Follow that up by using smoke screen to hide yourself and let the damage encourage Maeve to retreat.