1: I too have wondered about skin withstanding bombs. At this website http://forums.sjgames.com/showthread.php?t=92298 it talks about some nuclear testing data that was declassified in 2006. Among them the forum member noted
"In the 15.2 Kiloton REDWING-INCA nuclear test on June 26, 1956, 30 cm diameter carbon-coated steel balls were placed 9 meters from the bomb by researcher Lew Allen, and were undamaged with only a loss of 0.1 mm of surface graphite."
I did some calculations, pretending that steel ball was dead center of the blast instead of 9 meters away, and if Godzilla had scales that were the same concept as those steel balls he'd have to have them 22' in thickness to withstand a 340 Kiloton Nuclear Bomb (which is the max strength nuke used in modern times, particularly from Stealth Bombers).
So to make a realistic Godzilla capable of surviving a 340 kiloton nuke he'd have to have completely new unknown-to-science material that's thin but very tough. Using known Earth materials, at best he could probably withstand swords/knives up to gunfire from human soldiers.
2: Could be possible yes. If you look at the science of dragons, one thing they'd need is some kind of ignition to spark their flammable gas into fire. Godzilla is basically a wingless dragon so the same theory applies.
I believe in Jesus Christ, who's my Lord and Savior.
John 3:16, Job 41:1-34, Leviticus 18:22
