Do stats really affect the minimum and maximum HP and MP received on level ups. Is there a pre-set min and max that you will not go under or over per level up, or is this completely random and any number can be attained?
Stats can affect the level up gain. See below.

Are these actual random rolls or is there a pre-determined maximum that a character’s HP or MP will reach at specific levels.
HP is determined totally randomly at level up. For each class, there is an amount between a set range given (a random amount within that range, which is specific by class). Thus, knights will get potentially more HP per level up. Base constitution being high enough will give an additional bonus to the HP gain, i.e. CON 16= +1, CON 17 = +2, CON 18 = +3. Modification for mana behaves in a similar manner, by adding in modifications depending on class type with internal calculations against wisdom.

If your high level dog goes wild and you re-tame it, will it still be a high level dog?
No, a dog will default to it’s original level once it is re-tamed.

Are there base levels of damage for the “attack” spells?
A number of dice (explanation below) are rolled to determine the damage inflicted. The type of “dice” rolled is determined by the spell that is cast. As an example, if a spell did 4d8 damage, it would potentially do damage in the range of 4-32 points. The range of damage varies based on the spell and on spell bonus. Each point of spell bonus adds another “die” of the same type to the spell damage. So if one mage does 4d8 damage with their spell, a mage with 1 higher spell bonus will do 5d8.

Let me explain a little bit about “dice rolls”. Numbers are applied to weapons and spells that generate random amounts between a certain range of numbers. These numbers are all invisible to the player, and happen instantly. They are termed as “dice rolls” because of how the coding generates the numbers that total the damage. For example: If I were making a weapon that I wanted to do between 12 and 24 points of damage if it successfully hit, I would need to apply a number between 1 and 2, exactly 12 times. So potentially, I would have as few as 12 number 1’s in a row, totaling 12. I would have a maximum of 12 number 2’s in a row, totaling 24. Somewhere in between, I could have generated a few 1’s and 2’s, totaling somewhere between 12 and 24. A number “5d8” means a number generated between 1 and 8, done 5 times, and those 5 results are totaled into a new number. This is calculated by the game, in the coding. It is done instantly.

Are there benchmark levels of alignment which affect the performance of spells (i.e. 5k lawful = extra heal does xx, 10k lawful…etc)
Due to the way the math works and because healing spells can’t heal fractional damage, or heal as much as 32767 damage, the scaling based on alignment causes some implicit tiers that depend on the actual number of points that would normally be healed. Imagine how a heal that would normally heal 32 points of damage. Scaling that based 32000 possible alignments means that there’s implicitly a tier approximately every 1000 points.

How exactly does alighment affect casting spells (ie: does being neutral mean you do more damage with eruption?)
The only spells that alignment factors in to are the heal spells. Higher positive alignment results in more damage healed. Negative alignment does not reduce the amount of damage healed, its only a bonus for positive alignment.

I would also like the effect of DEX on accuracy. Does it only affect ranged damage, while STR affects melee damage or it affects both? My level 33 friend hit me once in 2 hits at -39AC with no DEX enchant, but I hit him every time at level 28 with DEX enchantment (21dex total) and he had -40AC.
Dex affects your chance to hit, in both ranged and melee attacks. It also affects damage on ranged attacks.

So does nutrition level affect your level up gains, as seen in some games?
No.

Do different items have different odds of blowing up on overenchanting?
No, except in the case of some elven armors as opposed to non elven armor. Some elven armors can be safely enchanted higher then non-elven armors. The only thing that matters on the rest of the items is the enchanted amount.

Does DEX affect how often monsters hit you? I’ve hunted DV with -39AC +6 rapier on a level 28 knight with 16 DEX, and the monsters hit me as low as 1 in 3, with a base ER of 11 (13 with DEX enchant).
Your character’s DEX does not affect how often monsters hit you. ER is what is involved in ranged attacks.

How does magic resistance work exactly? Does it lower the damage of spells, or it increases the chance of completely avoiding a spell? By how much does it affect the damage/avoid rate?
If you resist a direct damage spell, the damage you take would be cut in half. It also affects certain spells with non-damaging effects that can be completely resisted, such as paralyze, weapon break.

How does damage get totaled. As in, Rapier is 11/6. So would a +7 rapier do 1-11 randomly and then +7 (8-18)? Or would it do 1-18? Or 8-11?
You get the die roll for the base weapon and then the enchant value is added. A +7 rapier would get 8-18 damage. Damage is determined by first taking random value between 1 and the weapon’s base value for the target’s size. For a rapier, this would be 1-11 for a small creature. Then any weapon-based damage bonuses are added, weapon enchantment is added, the bonus for the enchant weapon spell is added (if any), opponent-specific damage bonuses are added (bless/silver against creatures they affect), erosion level is subtracted. If damage at this point is less then 1, damage will be 1.

What is the formula for going pk, such as if you are full lawful and you kill someone that is full lawful is it a set number that your alignment goes to? Or is it random?
If you are neutral or lawful and you kill someone who is neutral of lawful, you will go chaotic. How far chaotic you go is based only on your level and not your alignment or the alignment of the player you killed. If you are already chaotic and kill a neutral or lawful player you will go an additional 500 points of chaotic.