Rocketlab tried air recovery but no success so far

You definitely would feel the backward acceleration of both the gun and you moving backward. This is exactly because you and the gun aren't one single rigid entity. If you have watched any slow-mo gun firing footage you will see the gun moves first after a bullet is fired, then the shooter's arm starts moving a short while after. The same thing would happen in space.

The recoil suppression system doesn't eliminate recoil (only tiny amount of energy lost as friction, etc), rather it spreads the recoil over a longer time and redirect the force downwards.

Therefore the gun would act as thrusters just like any other guns.

If you would like a more mathematical/physical way of thinking this, try the conservation of momentum. When a shooter is holding a gun in space no moving, there's no momentum. As the bullet is fired it gains momentum. Since the recoil suppression system is part of the gun, naturally the gun and the shooter would be imparted with an equal but opposite momentum.

Lastly, tell your friends that recoil suppression system is 'supression' not 'elimination', the shooter can very clearly feel the recoil.

That cannot be it, since Artemis 3 is done entirely without gateway

That's entirely ignoring the cost and difficulty of setting up, running and maintaining a large industry on the moon. Even your base premise is wrong, the most expensive part of a rocket isn't the fuel, it's the rocket itself, that's why reusable rockets are the trend now.

Let's illustrate how unnecessary it is to refuel on the moon, then go to another place like for example, Mars.

It takes similar amount of fuel to go to Mars compared to the moon. What you are suggesting is that instead of launching and refueling from Earth, then head to Mars, we should:

1. Launch all the machines and equipments needed for a mining and refinery facility on the moon.

2. Assemble, run and maintain said facility with materials from Earth, because the moon doesn't have all resources needed to be self sustaining.

3. Launch a rocket all the way to the moon, land, refuel and take off again towards destination, in this case Mars.

There's all disadvantages and no advantage to what you suggested, it's like taking a massive detour to build a new gas station in the middle of nowhere just so you can continue on a trip, instead of going to the gas station nearest to you. I simply cannot see the value in setting up moon as a gas station of space, not with current and near future technology.

Which is more expensive, risky and complex than just sourcing from Earth

Exactly, the one running the most space tourism flights rn is Blue Origin which uses a hydrolox rocket that emits no carbon exhaust.

SpaceX is using RP1 but moving to cleaner fuel, the article is completely detached from reality.

Sure, but counting space power by order of things isn't really indicative of current situations. I wouldn't call Russia the 2nd space power rn even if they sent the MIR into space before China.

Just because they started 3rd does not mean they are locked in the 3rd place.

As far as manned lunar program goes America is the only one in the game, next is China. EU being a partner with the US and potentially China also means they will follow right behind the leaders. Russia has talked about a moon program but considering their situation rn I take it with a massive pile of salt.

Apart from that, Japan is on Artemis as well.

I feel like 1/yr is not remotely enough

"save money" do we know the opportunity cost of waiting for used hardware and paying idle fee vs whole new orion and launch the rocket?

Did those stages fall uncontrollably or was there a de-orbit burn?

Even then, are the Chinese really contempt to be compared to USA in the 70s?

Also, having unintended space junk left behind only hurts their business, so it is in their interest to make sure they have good control over their satellites.

Well actually NASA exec sold congress the idea of a shuttle derived launch vehicle