In first edition AD&D, ten coins weighed one pound, regardless of what metal the coins are made of. In second edition AD&D, fifty coins weigh one pound, regardless of what metal the coins are made of (DMG2, p. 134; DMG2R, p. 181). This should result in coins of different sizes, with copper pieces being much larger than gold pieces due to the weight difference between the two metals, but there is no mention of any such distinction in the rules. Historically speaking, coins of different denominations were of varying weights and sizes--making an accurate scale a merchant's best friend. 

Perception?

I read about the perception stat and its really pushed too far, like if you have a good perception(18) you can see 50X better then 20/20 vision. An eagle sees 20x better then that and is it has the best eyes on earth. And if you have a PER of 25 you can Can perceive subatomic particles and hear any motion of atoms on the atomic level??! Thats just non-sense.

Medieval combat wasn't anything like the way it is in D&D! 

The combat system in D&D is a gross simplification of real combat, designed to streamline the process of determining the outcome of such a situation. Many arguments about the reality of such-and-such a weapon's speed, damage, use, size, etc. usually based on personal observations and/or on SCA tournaments. One thing to keep in mind is that this is just a game; it is not real life. It is not meant to be extremely realistic. There are other, more detailed combat systems out there in other games, several of which take hours to determine one simple combat. 

Alignment 

Look in alignment and you will notice that there is no list for true-neutral. I personally do NOT LIKE true-neutral as an alignment. I believe that no person can be totally self-interested and be totally neutral in all aspects, and thus I think NN is an unplayable character (sorry to all the druids out there!). Any DM's who want true-neutral guidelines, I will just suggest you take something in between NG and NE, CN and LN, and go from there. Having a total neutral would be like fighting with aman that will aways swich sides and can diside on any proper type of action, because actions resault an evil or good consequence. 

Monsters: 

It seems that TSR can't seem to follow mythology details. The right histories of monsters TSR published: 

• The Golem: is a clay figure of a man that has been brought to life, and is documented in Jewish legend. Golem means literally a shapeless or lifeless clod. Eleazar of Worms has preserved the secret formula for making a golem. The procedures he lists cover 23 folio columns and require knowledge of the "alphabets of the 221 gates", which must be recited over each of the golem's organs. The word emet, which means "truth", is marked on its forehead. To destroy the golem, the first letter must be obliterated, forming the word met, whose meaning is "death". 
• The Vampires & Werewolves: are wrong but that's from Hollywood influence so not too much to blame. 
• The Chimera: A fire-breathing monster that had the head of a lion, the body of a she-goat, and the tail of a dragon.

A discussion with Theodoric, having researched historical armor thoroughly , I can tell you with some certainty that everyone at TSR has screwed-up. Take for instance the dominance of chain and plate in the game. Chain mail is in fact inferior to scale armor, but is givin a better AC. Medieval knights didn't wear chain, they wore solid or banded mail, where rings were overlapped in rows on a backing of leather. In artwork, it is very often confused for chainmail, but in fact is much heavier and provides greater protection that scale, formerly the heaviest armor available. Then there's plate armor. Plate armor developed to counteract early guns, not bows, not crossbows, guns. How many AD&D campaigns do you know of that have firearms like those found in the Three Musketeers? That is the time period most campaigns are set in, given the high levels of technology. They are the result of consulting over a dozen books on armor. Normally, I allow critical hits to strike the head, thus leading to some interesting wounds, but I role-play it as much as possible. Beware of most of what you find or are sent on the subject, most people have a completely erroneous idea when you speak about a particular suit of armor, thanks mostly to Dragonlance artwork and the Arms & Equipment guide, which is a terrible form of historical standpoint. It's my opinion Gary Gygax was the last person at TSR to check his sources or even do research. That was a heck of a long time ago. People on the net are even worse. Most have no idea how battles were fought, or why certain suits were favored above others. In fact, all AD&D armor is piecemail, just already layered into suits. Splint armor includes padded, scale, mail, and even plate defenses. You might pick up the original edition books (PHB, DMG, Unearthed Arcana), for this is where the definitions of the armor types were first presented clearly, and are Gygax's thoughts on the subject. 

Comment: About the guns...actually, other way around. Original plate mail was developed before guns. Guns were developed to counteract plate-mail, making it obsolete. Plate-mail was then made thicker, so thick that a knight had to be hoisted onto his warhorse by a crane, and if he fell he was often helpless. It was around this time that the use of metal armor in general began to fade, until it eventually was needed only for ceremonies, as it is used today (i.e., the pope's Swiss Guard).  

Guns have been around since the battle of Hastings. Plate mail, yes, was developed before practical firearms, but the Gothic plate armor (field plate), and the heavy plate of the renaissance (full plate) were designed to deflect and stop guns. Thus plate (as most gamers view it) did not exist without the gun. In fact, splint armor was heavier than the plate mail worn during the crusades, but was also much bulkier.