"Elements" within gaming
These two topics, as FleBlanc already stated, are an abstraction layer of reality. The four elements are incredible good design, because they are highly abstract, unique and are able to counter on other element. Hit points are although a very good abstraction still used in almost any game available. Sometimes you just have a single hit point, sometimes the hit points are hidden (CoD?), sometimes they are just a percentage, sometimes they increase with experience.
Condition not Damage
Many strategical war games use a very high degree of abstraction (go, chess) and have still very interesting gameplay. to offer. The issue with modern games is, that they often try to be more movie-based-story-telling-eye-candy than actually game. Sometimes the limitations of previous hardware generations forced the developers to concentrate on the gameplay, which was often a blessing from a game design perspective.
In general gamers don't like to loose the control of the game, e.g. when taking away the control in a cutscene or when the executing of a command failed due to some lag or preformance dell. Therefore performance should not hinder your game experiences. Many reaction based, competive games need to deliver high enough performance to not hinder the game experiences, but slower single player games or MMORPGs are more low performance tolerant. The real performance requirements depends heavily on your game design.
Performance and It's Effects
I played everquest with very high lag sometimes (500-800 ms), whereas I know Quake 3 gamers who disabled every single eye candy to gain just an other FPS .
Many people, including myself, don't want to talk about their ideas, because they think, that their ideas are somewhat special or unique. But I think, that the development of an idea depends a lot on the zeitgeist and external stimuli which are plenty in times of global media and internet. Even historical scientific discoveries have been researched independently by several people concurrently, long before global media.
The main thing is, for me, it's uncomfortable to share ideas.
In short: there are not really unique ideas, in fact each idea is only as much worth as its implementation, best example:
What Apple did was execute better on those ideas than others who had them.