Here\'s an arguement I hear way too often. There are too many rules. I say better too many than too few. Have you ever played in a group that won\'t accept that DM is GOD??? it\'s not a pretty sight. the entire group ends up unhappy. The players argue that they automatically have all kinds of abilities that give them unfair advantages in combat... your ambidexterity arguement perhaps. how else is ambidexterity to be controlled, without that rule, you\'d have an army of dual weilding warriors and rouges in every campaign. there are rules that I don\'t agree with in third ed, but as a DM, it\'s at my discretion to change them. that\'s the beautiful thing about tabletopping, (better name than pen and paper) it allows any rule to be changed within reason.
one of the best reasons to have lots of rules is that often an arguement will arise that requires a logical responce that the DM might not have forseen. say in the case of a character and a monster having the same initiative, how is the situation handled? it\'s covered in the DMG. however, if the DM is not satisfied with that rule, he can make a house rule that contradicts the book rule. just so long as there is a rule in front of the players that cannot be argued with, the DM can point to the rule and say \"this is how it is, if you don\'t like it, tough\"
I\'ve run into some sticky situations with \"powerplayers\" people that are just fine with a game as long as they can play it to their advantage. but as soon as the situation turned against them, they tried whining to me to bend the rules in their favors, and as long as I\'ve got the book in front of me, and a poster with house rules behind me, I have no reason to give in.