Honestly I'm the same I like the end of the clip too, no offence to Tracy fans but I don't like her 

Tracy was cool. I'm not surpirised that Theo took her powers, everyone should've seen this coming. I'm more surprised at the fact that she can't take pain even though she's part werewolf.

Eh I'm not into Malia and Theo, Theo had many opportunites to redeem himself, but he continues to kill his own for power, hence he's becoming a foul beast.   He's already absorbed many of his own's powers, making him pretty over powered and too strong to be on the show, other than a villain. Hence, he probably will die.

I really don't want Theo to die. I see where your coming from with the powers situation. I don't think it's actually been established if Theo actually inherits their powers or just their strength, I've no idea So he is probably going to get himself killed or badly hurt going up against Sebastian/The Beast because some of his Pack have abandoned him and not to mention he's pretty much killed 2 already so it could become a situation like the twins like they lost their Alpha status after they were badly injured by Jennifer but who knows its team wolf anything can happen :)

^ Theo inherits their power as well. That's the only way he was able to wear the mask and not die. Without Josh's power, the mask would've killed him. Also he needs Kanima venom to paralyze the beast, so he would need Tracy's power for that, so I think its more than strength, its their actual ability. 

Theo can't be redeemed. The doctors confirmed what most of us already knew, Theo was born evil. He's a sociopath.