[lacer]

It's not necessarily forcing third partying. If a KOSed T is near you and you are clearly aware of them (i.e. staring directly at them) and you are not attempting to act on the KOS, that absolutely should be KOSable. If you die, it's your fault for not acting on the KOS. 

Also, have two addendums to that rule:
If the KOSed person in question is not a T, or the person who did not follow the KOS is AFK, you cannot be sused/KOSed for not killing them.

But, as a T  I like to false kos, so why should someone who knows that I like to false KOS follow a kos they could possibly know is false, it should be left up to choice, not forced by third parties.

You're missing the point. It's not forced. You should simply have the option to kill somebody for not following a valid KOS.

If someone dies to a false KOS by a T then oh well, that's just what happens.