Screenwriting Question

My understanding is that you have to get permission from the copyright owner before using any of their proprietary characters, plots, concepts, etc. With a television show, I imagine you would need to option the property. The cost of that would be negotiable, depending upon the show, its residual popularity and what the market will bear.

Why not write roman a clef?

I think that is true for a shooting script but I don' know if it is necessary to do that for a speculation script. I guess I will have to look into it more.

I do not know the answer to your question however I guess it dpends on how much is actually copied or whether you use the original as "inspiration"

In 2004 a movie was made in Australia about 2 men who pretended to be Gay to get financial benefits from the government, some time later an American motion picture company produced a very similar movie. I understand legal action is pending.

Strange Bedfellows is a 2004 Australian film starring Paul Hogan and Michael Caton as heterosexual men who pass themselves off as a homosexual couple in order to get financial benefits from the government. A very similar plot was later used in the American film I Now Pronounce You Chuck and Larry, and there is some controversy that Chuck and Larry may be a clone of Strange Bedfellows.
http://en.wikipedia.org/wiki/Strange_Bedfellows_(2004_film).

Seems to me you could write a synopsis and send it to them, but don't give them too much leeway to steal your story!