I think many here have answered the first point about those who don't fight.
On the second point, the kingdom preaching work, this was for me the hardest part to grasp. I did, but it took me time.
What does the preaching the good news of the kingdom mean to JW's?
It means preaching that Jesus Christ began ruling as King in 1914 when the Gentile Times ended and that the period of time time we are living in since then are the Last Days that Jesus spoke off. This time leads up to Armageddon whereafter a 'Great Crowd' of survivors will live forever on a paradise earth.
Problems:
1) Jesus spoke in Luke 21:23-24 that "Woe to the pregnant women and the ones suckling a baby in those days! For there will be great necessity upon the land and wrath on this people; and they will fall by the edge of the sword and be led captive into all the nations; and Jerusalem will be trampled on by the nations, until the appointed times of the nations are fulfilled."
Everything Jesus says above is clearly in the future sense (emphasis mine). So in 33CE he was talking about 70CE when the Romans come back. So the Gentile Times star in 70CE? No - even though everything Jesus says is future state, JW's (and others) apply the start of the Gentile Times to other dates. In JW's case it's 607BCE.
2) 607BCE.
What do I write? It's utter nonsense. Do your own research into it. For me what did it was the HUGE amount of evidence for 586/587 and absolutely nothing that supports the WT's chronology. Nothing. Whatsoever. By that I particularly mean the extra years the WT addds.
3) Where the Great Crowd goes.
They are in heaven. No - really they are. Check out the Greek word for before (enopion) and the where they are Naos. Combine those two and you get to the realisation that they are in heaven.
So...where does that leave us.
The JW's are preaching that Gods kindom was established in 1914 (not true).
That therefore the Last Days started in 1914 (therefore also not true).
And that the Great Crowd are on earth (also not true).
The three points above mean that Almighty God Jehovah, who hates a liar, is behind the group who are indeed going door to door...but with a false message! And they're doing this when Armageddon is totally and absolutely imminent.
So...are they really fullfilling the kingdom preaching work?