Enchanting unarmed strikes or natural attacks is a bit complicated.
For this question assume a character with at least a level of Monk - so improved unarmed strike and the extra rules re Monk's unarmed strikes (any limb, treated as both natural weapons and manufactured weapons for purposes of magical effects/enhancements.)
My question(s) are - how is stacking of multiple enhancements handled?
A few simple examples:
Amulet of Mighty Fists +1 & Magic Weapon/Magic Fang cast on the character - I think these do NOT stack resulting in a continued +1 enhancement bonus to the monk's attacks?
Amulet of Mighty Fists Flaming & Magic Weapon / Magic Fang cast on the character - here I'm not sure what either RAI or RAW is. Does this result in the monk having a +1 to hit & damage + flaming (if activated via a standard action)?
Amulet of Mighty Fists (static bonus or special ability) and the character is a monk/maguc and spends a point of Arcane Pool. (This is apparently debated whether a magus can enhance an unarmed strike - in the case of a monk I think the answer should clearly be yes but others argue no it isn't a "held" weapon). Likely this results in a single attack being enhanced by the arcane pool & all other attacks also being enhanced by the amulet - but this is where I'm not sure how enhancement bonuses stack or do not stack. (in place of the Amulet consider Arcane Pool and Magic Weapon being cast - does that stack? Does the Magic Weapon spell if cast first allow the arcane pool be used for special powers (if the Magus is high enough level?)
Amulet of Mighty Fists (either static bonus or special ability other than Corrosive) and Deliquescent Gloves? - this seems fairly clear from the wording of the Gloves which implies that it would stack with any other enhancements (i.e. specific overrules general)
The wearer’s melee touch attacks with that hand deal 1d6 points of acid damage. If the wearer uses that hand to wield a weapon or make an attack with an unarmed strike or natural weapon, that attack gains the corrosive weapon special ability.
(also grants protections against oozes and slimes and doesn't split them etc)
Besides the Magus there are a few other classes with abilities that can enhance a weapon they are using - the Paladin's Divine Bond for example. Could this be used to enhance unarmed strikes? (I think so but not certain) and if so, would this stack with any other enhancement sources?
In all of these cases does any limit(s) apply to the total effective bonuses on the attacks? (i.e. the usual max of +5 enhancements or +10 total enhancements? Does the Amulet's specific restriction to +5 total matter in any way here (or since it is the limbs not the amulet being further enhanced by spells/class abilities the amulet's restrictions don't count here?
Sorry, I'm not sure. I'm curious too though, since I have a nat-attack catfolk about to dip monk. I DO know that you can combine style damage (example, boar shred and elemental fist) and precision damage (sneak damage from a rogue dip), but Im unsure about the item conflicts...
They do not stack, they overlap.
In the case of a Flaming AoMF and +1 from Magic weapon yes, they overlap to produce a +1 Flaming effect that only bypasses magic.
To take this further, if you have a +2 Flaming AoMF and have +5 Greater Magic Weapon cast upon you then you have +5 Flaming.
Deliquescent Gloves would add the Acid to all of that.