These all can be done with Current elements.
Use dlay for slow conduction,Heac for fast heat transfer.
Or make a lua script element.
Lead has more neutrons than gold, so it should be the other way around
Excuse me for the necro, but TPT isn't meant to be totally realistic.
This is a borring and unrealistic sugestion
NUCLEAR FOX: *chuckles* I know that. But tpt IS meant to be mostly realistic. Because that's what it is.
I just realized something. Tpt DOES have lead. Mercury is liquid lead. Just use the console to solidify mercury, and you got lead.