Yes I was thinking of the defenders, seeing the attack and being told when to open fire.
Again entirely dependent on the tactical situation. You'd generally want to open fire as soon as they were in effective range, casualties at long or extreme range (up to the effective range of the weapon) are still casualties. There are tactical factors for why you'd hold your fire, perhaps ammunition would be one or not wishing to reveal your location until the last minute (a tactic seen in use both by the late war Germans and VC - stay close to your enemy so he cannot bring his superior firepower to bear) but these will only apply in certain circumstance. A typical tactic in Afghanistan is for a Taliban 'sniper' (a guy with a gun) to pop off a few rounds at extreme range and then leg it. It'll slow the coalition troops down as they take cover and try and work out the position of the fire, by which time the 'sniper' is long gone.
Attackers fire whilst moving far less effective.
Yes it is. That should be reflected in the rules, thus the need for 'pepper potting' tactics or establishing a base of fire. Aimed fire from a stationary position will always be more effective than a quick snapshot or trying to fire a weapon on the move.
The 'leap-frog' approach to attacking does not seem in much evidence.
Well apart from being the standard tactic in British field manuals to the present day... I've spoken with Falkland verterans and I have two friends in the 3rd Batallion Rifles. Its still very much in use.
The standard german tactic of WW2 by the way was to either rely on surprise or their support weapons so they could take a position as quickly as possible and then hold it with their machinegun. That meant the Germans were generally quicker on the assault than the Allies, their tactics echoing the Stormtrooper tactics of WW1.
The real question is, if ranges are effective ranges how much more effective are they if the range decreases. So lets say effective range is 50% chance of a hit, at what range does that chance to hit (more effective shooting) become significantly greater?
The problem with your statement is the use of the term 'effective'; once you understand what effective means in Military terms you're closer to unravelling the knot. Look at different websites and you'll find different answers, with the typical east-west bias. After you've read yet another site harping on how inaccurate Russian assault rifles are you realise they've missed the point. The Russian's design philospophy is entirely correct for their doctrine - suppression. Which leads us back into the 5.56 debate - 5.45 or 5.56 does the supression job just as well as the heavier rounds and your infantryman can carry more of them.
The effective range of a weapon is the range at which it can still do its job - incapacitate or kill the enemy. Think of it as maximum effective range the weapon is capable of killing. Now a machinegun has a larger effective range than your average rifle, why is that? Its down to the fact that it can fire a greater volume of bullets at the target and so the chances of it getting an effective hit at longer ranges is greater.
Liked the article, wrong about the Boer war of course as infantry continued to advance against enemy rifles (as shown at the beginning of WW1). Machine guns and artillery really put a stop to the open warfare.
The reasons why they advanced has much to do with the British army doctrine of the time, like the German army, some commanders were rooted in the old style tactics of grouped formations of men and volley fire (the 'mad minute' by the way was controlled volley fire). A few commanders, who'd served in the Frontier in India, had learnt to let their infantry skirmish to reduce casualties but lessons weren't learned until the Boer war.
You could argue that machineguns and artillery later opened up open warfare, as the article says the game is about preventing your enemy from firing back, supressing them. The Blitzkreig being a classic example of combined warfare to breakthrough the enemy and it should be remembered that very, very few of the German infantry divisions were mechanised in 1940.
Sorry, when it comes to guns I've done a lot of reading!