At first: I didn't read every page of this thread, only the first three and last three pages...so if anyone else had my ideas before, sorry. btw: I also read the FAQ... Also my english isn't the best, so please ignore mistakes
Now to the ideas: Hydrogen(i think a lot of people had had THIS idea): VERY light gas, highly flammable, in contact with O2 it becomes(after some time) water, gets liquid at deep temperatures, maybe at very high temperature it becomes plasma(like in hydrogen bombs), but i think NBLE does the same effect...
Nitrogen Gas(i wonder why in PT there is NICE and LN2 but no N2): gas, nearly as light as O2, extingishing fires, gets to LN2 or NICE at deep temperatures
Noble Metal: solid, isn't attacked by ACID, melts at high temperatures(maybe like platinum at 1770° C...hmm, yes, "high" )
Chlorine: gas, "bad" for the stickman and plant
Sodium: solid, same effects like RBDM(except the melting point), becomes with chlorine SALT...of course with a big boom
Sodium Hydroxide: liquid, same effects like ACID, neutralizes ACID(becoming SLTW, I assume that ACID is hydrochloric acid)
Maybe solid PLUT and URAN
And some other suggestions: Something like electrolysis (with ACID and SLTW): with ACID you can make hydrogen and SALT, with SLTW you can make chlorine, hydrogen and sodium hydroxide
Something like pyrolisis, maybe when you put WATR at burning THRM it is becoming hydrogen and O2
In closed rooms, in which only NBLE and maybe WOOD is in, the wood is burning. That's not very realistc...
Oxygen is not flammable!
A function, that COAL becomes under high pressure and high temperature diamond...
I understand if you can't put all of that in a new version of PT, but I am happy if there is only one of my elements or functions in it.. Well, thats enough...for now...