With regards to the high/hot/unstable scenario, I think everyone has valid and true points, lets just put it all together. You are at the interview for your dream job, then told your'e the CA(PNF) in the above scenario, now WWYD? (Take controls? Let them learn the hard way?) I think we'd all be singing a different tune to the interviewer.
This is a good CRM scenario. It starts with a brief of ATC procedures as a threat, and no you can't brief every scenario. You can say "they like to leave us high and turn early here, so, uh, watch out there buddy" til your face turns blue. And yet, magically a few minutes later, you'll be squirming in your seat wondering when you're gonna get dirtied up properly. Just talking about it prior should mitigate the threat in most cases. But if it doesn't, then what? Like Jtrain used, a subtle cue like "would you like xxx" or "we are still showing a little high" is a soft prompt, and usually enough get things reversed. It says I'm concerned, but I'm not trying to be controlling. Now, if that doesn't get it done, and you're approaching unfixable territory, use the more urgent and commanding "we need to drop the gear","if we don't slow now we we wont make it", "I'll ask for S-turns". That takes the guessing out of it. You do all that before you get to the point of no return. And if for whatever reason it still just doesn't work, go-around. Then, talk about it at the gate. Whether its from a pride deflating go-around or just feeling dumb because the other guy had to step in, the PF should be humbled sufficiently to learn what to do next time. Good CRM doesn't need to go from zero-to-my controls, nor from subtle hints-to-passive aggressive "fine I'll just watch you screw it up" either.
Also, if this is about new guys, here's another angle to look at. We all hope they keep us in the loop and ask for guidance on the fly. This is at the heart, a communication issue. They are likely thinking "Am I looking okay?","Should I start down now?", "FLCH or VS/FPA?", "Is it too early to put flaps(#)/gear down?", "whats fastest way down right now?", and if they would only verbalize that, everything would turn out like it should. But they likely won't because, well, we all have an ego and want the other pilot to think we are a good pilot. Because good pilots don't need help, right? That insecurity hurts CRM, and being aggressive or passive-aggressive as a CA only deepens it. Hopefully we briefed open communication and showcase an approachable vibe so they feel comfortable asking questions. And if they don't verbalizing their thoughts and screw up, and we counter that with good CRM and a constructive debrief, they will hopefully trust us enough with their insecurity to fit in and actually use us as a resource.
