|Pathfinder Adventure Path Subscriber||
This might be better to the house rules section of the boards but for the sake of helping a new DM here is my list of house rules:
1) Spontaneous casters have normal casting time when using rods.
2) Vital strike works on charge and spring attack but not pounce like and spring attack like effects.
3) Half-orc ferocity is the same as orc ferocity.
4) The paladin's capstone banishment effect doesn't end the smite if the evil outsider makes the save.
5) Monks are proficient with all monk weapons.
6) No leadership.
7) No antagonize.
8) All PrCs that give spellcasting level increases also gives spell known for spontaneous casters.
9) All rods are considered light maces.
10) The rogue talent combat trick can be selected more than once.
11) The snap shot line and the zen archer's reflexive shot work.
12) The scatter firearm attack can't be used when using the smiting shot deed.
13) Haste can give an extra attack with unarmed strike.
14) If you have double slice then when you use power attack you get the -1/+2 ratio with your off hand attack(s).
15) Flaming and similar elemental weapon enchantments require a free action to activate instead of a standard one.
16) Flaming and similar elemental weapon enchantments can be upgraded to burst effects by adding +1 enchantment worth to the weapon.
17) Low and medium fortification armor enchantments can be upgraded to medium and/or heavy fortification enchantments by paying the (enchantments cost) difference. The same thing applies to the shadow, slick, energy resistance and spell resistance armor enchantments.
18) The +2 to attack and damage rolls of the bane weapon property can't be used to add more than +5 (overall) to the attack and damage roll.
19) The +2 to attack and damage rolls of the furious weapon property can't be used to add more than +5 (overall) to the attack and damage roll.
20) The oathbound paladin's aren't required to have one of the listed gods as a patron deity, instead there are some gods that if being a patron for a paladin then the paladin are excluded from taking a particular oath (example: Abadar and Shelyn for oath of vengeane, shelyn and Abadar for oath against undead, abadar for oath of charity etc.)
21) You automatically disbelieve your own illusions.
22) Runestones of power can hanged in the character's body (neck, wrist etc.) without occupying the slot and can be used as long as the caster has one hand free.
23) Clerics and inquisitors of deities who have a simple weapon as a favored weapon gain weapon focus with that weapon for free at 1st level.
24) Rods and staves can be enchanted as weapons without the +50% to the price of the magical enchantments.
25) Echoing spell + spell perfection does not equal infinite loop.
26) The guardian weapon special ability does not work with GMW, also the it can't be put in a non-hand held item, in addition it can't be put to either armor spikes or shield spikes, also the hand that weilds the weapon with this property can't be used for anything else other than attacking.
27) You can't weild armor spikes without TWFing.
28) Wildblooded bloodlines are valid targets for the eldritch heritage feats.
29) The Paizo blog on intelligent animal companion is mostly disregarded.
30) Both the skill focus feat and CHA requirements for the eldritch heritage feat line is disregarded with DM's permission (no you can't have your CHA 7 fighter with abbysal or orc bloodline).
31) Both the powerful sneak and the deadly sneak rogue talents don't carry a -2 penalty on attack rolls when used.
32) The rogue talent hide in plain sight also can be used if the chosen terrain doesn’t grant cover or concealment.
33) Oracle mysteries aren't tied to specific deities.
34) Conductive weapons of any type can be used for either melee or ranged sorcerer's bloodline abilities.
35) The spell focus, greater spell focus, elemental focus, greater elemental focus, spell penentration and greater spell penentration feats can be chosen as a wizard bonus feats.
36) Arcane armor training and arcane armor mastery do not require a swift action to use instead they are permanent effects.
37) Weapon proficiencies do not have +1 BAB as a prerequisite.
38) The heavy repeating crossbow costs 75gp.
39) The light repeating crossbow costs 50gp.
40) Torag has the War domain and the tactics subdomain (in addition to the normal list of domains and subdomains).
41) Cayden Cailean has the Liberation domain and the freedom subdomain (in addition to the normal list of domains and subdomains).
42) Crossblooded sorcerers have a minimum of 1 spell known at each spell level.
43) Crossblooded and the Wildblooded archetypes can be used together.
44) The Dazing spell metamagic uses a slot 4 levels higher instead of 3 (metamagic rods of metamagic are priced accordingly), in addition each round on its turn, the subject may attempt a new saving throw to end the effect as a full round action.
45) The snowball spell belongs to the evocation school and is subject to SR.
46) If a subject makes the initial save of the terrible remorse spell then the subject isn't staggered but only takes -2 penalty to AC.
47) The burning disarm spell has a will saving throw instead of a reflex one. In addition when the subject makes the save he takes 5d4 fire damage, when the subject fails the save he drops the held item.
48) The emergency force sphere spell is a 5th level sorcerer/wizard spell instead of a 4th level spell.
49) The acute senses spell gives a +5 enhancement bonus on Perception checks (+10 at 8th caster level and +15 at 16th caster level) instead of +10 (+20 at 8th and +30 at 16th).
50) The subject of the spell irresistable dance, who made his save, can act normally (but take the associated penalties) while dancing for 1 round.
51) The subject of the spell suffocation who makes his initial save isn't staggered.
52) The spell feeblemind doesn't carry a -4 for it's save for arcane caster subjects.
53) The subject of the spell cacophonous call each round on its turn, ay attempt a new saving throw to end the effect as a full round action.
1) No guns.
3) No eastern weapons and armor.
4) No gunslingers.
5) No archetypes of any class with guns.
6) No samurais.
7) No ninjas.
8) No summoners
9) No monks.
10) No witches
11) No paragon surge spell.
1) The qinggong has the option of swapping a monk power or not for a qinggong power, meaning that he can select other archetypes by forfeiting the choice of the power selected.
2) The rogue talent offensive defensive doesn't stack with itself.
3) The double pistol doesn't give you manyshot for every attack you have, by firing both barrels you simply get double damage die.
4) The lightning reload deed allows you to reload as a free action any firearm as long as you use alchemical cartiges or have the rapid reload feat with that weapon.
5) When picking the sylvan bloodline for eldritch heritage you gain the animal companion.
6) The sable company ranger archetype only gives up the first favored terrain.
7) You can't use somatic components when using most of elemental body forms.
8) You can use somatic components when using most of monstrous physique forms and most of undead anatomy forms.
9) Your equipment resizes when using monstrous physique.
10) Thassilon specialists also get the arcane school powers and can choose a focused school if they wish.
Keep in mind that my list is fairly old (a little more than a year) and i didn't have to update it. Also keep in mind that this list is, mostly, things i have changed about the rules, campaign specific stuff like no evil alignment or core races only aren't included.
As to your other questions:
When do you enforce a rule? Always (or rather almost always)
If I allow someone else not to follow a rule, do I have to do that for everyone? Yes everyone (keep in mind that this means NPCs too).