If sarin gas is outlawed, only outlaws will have sarin gas, right?

Not sure what side of the issue you are on, but your question actually strengthens the "gun rights" argument rather than the "gun control" argument. Case in point, the Geneva Convention is a list of rules for war, but it is generally ignored by "rogue states" and terrorists or "outlaws" such as Iran, the Taliban and Al Qaeda, to name a few.

As a further point, no one wants nuclear or chemical weapons in the hands of rogue or unstable nations but they continue to acquire them (Pakistan, North Korea and, inevitably, Iran, at some point). The only thing keeping these states from using their nukes or chemicals is the knowledge that most other nations have them also and will blast them into oblivion should they ever choose to push that button.

Oh, I don't know, you'd think so yes? Same with Zyklon B. Yet, it is unavoidable that many things are kitchen capable of being made. Like phosgene gas.

However, yes, it also follows that if assault prevention weapons are suddenly made outlaw? Then many citizens instantly become outlaws. Same as a deadly gas.

Here's how it would go with firearms/assault prevention weapons.

“Those now possessing weapons and ammunition are at once to turn them over to the local police authority. Firearms and ammunition found in a Jew’s possession will be forfeited to the government without compensation. Whoever willfully or negligently violates the provisions will be punished with imprisonment and a fine.” Nazi Law 1938---Or Gov. Cuomo 2013?

Some bad people do have sarin gas the only problem is that illegal guns are pouringvinto this country because a certain president aka obama will not close off our border with mexico he even sells guns to mexican cartels

It is probably easier to make sarin gas than guns. Still, sarin gas should be outlawed and guns highly regulated.

Several republicans have claimed that the second amendment allows them to own tanks and nukes..."if they wanted to do so". They believe that they should have ANY weapons that the military has.

If China would manufacture small canisters of it, then yes, outlaws would have them

There is no constitutional guarantee of your right to own poison gas.

And if having a steak knife is considered being "armed," then only the "militia" can have one?

Actually, yes. You can legalize it and I'll still have little need or desire for it.

My gun on the other hand can defend my family.

Exactly. Some weapons freaks don't want it until someone says they can't have it.