I agree, the pre-WWI high command were planning freaks. The Prussian army had succeeded by being precise and prepared.

I understood from the pre-war diplomacy was the back and forth between the alliance members was the desire to show commitment. While the English may have claimed they could keep the French neutral, i am not convinced the French didn't also 'want' war in some respects. They definitely wanted revenge - a rematch of 1870. Of course, the Russian hordes breathing down the Germans necks would give them a greater chance of success.

Everyone had their reasons not to back down - fail to support an ally weakens your value as an ally and could result in isolation. The Germans probably believed they could take out any other, single European power (rightly, I think - as Dan Carlin discusses, the imperial german army in WWI was amazing). This meant that France couldn't not support Russia for fear that if the tables were turned (Germany threatening a French dependent state), the Russians would not come to their aid.