I can agree with some of your points, but some of them, IMHO, are worth complaining about:

Quote Originally Posted by Moah
Complaint: Infantry bugs (shields and 2H) make all infantry too weak. Cavalry are unbalanced and unstoppable. This makes infantry useless and the game unplayable.
What's bothering people (or at least me) most about those bugs is not that certain units fare badly vs cavalry, but that the bugs render them either at a senseless disadvantage (e.g. professional spearmen losing to peasants because of the shield bug) or utterly useless (e.g. billmen don't get to kill anything because of the 2h-bug).

Quote Originally Posted by Moah
Complaint: Passive AI is too weak. Too easy to win and the game is unplayable.

Complaint: Diplomacy is broken. All AI factions go to war and attack you. The game is unplayable.
Those two do not contradict each other. It often is to easy to win the battles because of the passive A.I. (which still happens in 1.1 occasionaly), while on the Strategic Map, it is nearly impossible to keep the peace, let alone alliances, because of wierd diplomatic A.I.. This can hardly be ignored and, IMO, deserves to be complained about and discussed.

Quote Originally Posted by Moah
Complaint: Longbowmen are underpowered according to history. Billmen are underpowered according to history. Knights are underpowered according to history. Spearmen are underpowered according to history.
To some, and apparently to you as well, historic accuracy doesn't matter much. For others, historic accuracy is a major factor in how deeply they can immerge in the gaming experience. Medieval 2 (and the Total War series in general) claim to be historic games, and it is obvious that some changes have to be done to ensure a certain level of balance. However, some of the changes (for want of a better word) 'destroy' the required level of historic accuracy required to captivate many players (such as longbowmen taking way to long to reload in comparison to crossbowmen). Obviously, those who do mind a degree of historic accuracy, complain about the situation - and rightly so!