As for Wild Shape, equipment really shouldn't transfer bonuses. But way back when Monk/Druids were largely the only druids on the server for the obvious reasons of transferring that buffed up 42+ Wisdom ability score to 16+ points of extra AC.
Thus the Dragon Shape that had the base AC of 28, would become 44 with Monk wisdom AC. After applying Tortoise Shell for +9 AC, the shape would have total of 53. (I think you used to be able to get +12 Natural Armor with Tortoise Shell...) Oh, Cat's grace gace +2 AC for a total of 55. Not to mention that with Natural Spell you do not really need AB as you can just sit inside a Storm of Vengeance/and other AoE spells... Thus Improved Combat Expertise gave +6 AC for free to a total of 61. Oh, you could easily grab Luck of Heroes for another +1 AC and total of 62. Wait, you can also have Tumble as class skill now, so that gives +3 AC to a total of 65...
So yeah, Dragon Monk/Druids used to be able to get AC of 65+... While retaining the ability cast spells. Oh, wait, it could be higher if they bothered to get wands of Improved Mage Armor for +6 AC, and wands of Shield for another +4 points of AC, so...
Dragon Monk Druids with UMD used to be easily able to get ACs of 75+...
And yeah, you could squeeze few more points more still.
Thus there was the ban on Monk/Druid multiclass, and many Druids (Monk/Druids) were quite unhappy about it. Thus, they got the following perks:
- Your highest enchantment bonus to armor or bracers will transfer as an enchantment bonus to AC (+4, or +6 with wand of Improved Mage Armor)
- Half of your enchantment bonus (rounded down) to your shield will transfer as a shield bonus to AC (+2 or maybe +4 with the Shield Wand)
- Your highest deflection bonus will transfer as a deflection bonus to AC (Halo of Sand spell for +4 AC)
- Your natural bonus will transfer as a natural bonus to AC (Tortoise Shell +9 AC)
- Dodge bonus does not transfer to AC
- Multiple instances of ability enhancements do not stack (You can cast +4 spells, and one +12 one)
- For a given skill only the highest bonus is kept
Druid can have AC of:
29 (Elder Air Elemental)
+1 (Luck of Heroes)
+3 (Tumble from multiclassing)
+6 (Improved Combat Expertise)
+2 (Cat's Grace)
+6 (Improved Mage Armor?)
+4 (Shield wand?)
+9 (Tortoise Shell)
+4 (Halo of Sand)
= 64
So I guess there could be discussion on whether Shapechange/Polymorph Self should have similar item transfer taking place... It doens't really change anything for the arcanist who got their buffs naturally, but I guess it is a topic for the Shaman to consider.