Blackcoffeenosugar, We could sit here and make up scenarios all day, it is all a bit pointless though, sitting at our Computers we all do the right thing and know all the answers. How you will react in the heat of the moment is another thing entirely.
As for ignoring SOPs, approach gates and airfram limitations etc, it is a difficult position for any Captain to put in an F/O in intentionally and most appreciate this and don't do it in the first place. Thankfully foolish remarks and attitudes like 411As are becoming less common in the industry.
In relation to unstable approaches, A large European low cost airline I am familiar with has had a high incident rate recently. I had the opportunity to see these incidents replayed on a computer program that used the FLIDRAS data to display the flightpath with a display of the aircraft from the outside in relation to the airfield and the runway (think Flightsim style) with the engine parameters and the Primary flight display (ADI, VSI etc). These incidents were quite shocking and frightening into how dangerous a situation and how far they were allowed to develop before a halt was called. No Crew sets out to intentionally let these happen.
Interestingly they were all flown by the Captain. This is a point made not that the F/Os can get one up on the Captains but it shows thet Captain suffer from Task overload/saturation along with F/Os. They suffer to such a point that they become incapacitated to an extent. However in the case of the F/O being the Pilot flying the natural Cockpit Gradient means a Capt would have no hesitation in calling a Go Around when an unstable situation develops. When a Captain gets overloaded, and lets face it; is suffering a form if incapacitation, for a F/O to assert his/her position is by the very virtue of the gradient and rank not always the easiest thing to do.
The company I am familiar with has changed the callouts on approach from "500" (Feet) to "500, Continue" in the case of all being well to "500, Go Around" in the case of an unstable approach. The thinking being that it obliges the F/O to say something, and not sit in Silence. It is also a timely prompt for a Capt. suffering a mild form of incapacitation.
A "text book" example of this scenario:
http://www.aaiu.ie/upload/general/6946-0.pdf