Southern Magician feat as prerequisite for arcane/divine casters

Question

I have trouble understanding the details of the full scope of the Southern Magician feat:

Southern Magician [General]

Your magical studies in Mulan lands have taught you spellcasting techniques unknown in the north that blur the line between arcane and divine magic.

Prerequisite: Mulan human, ability to cast 2nd-level spells.

Benefit: Once per day per two spellcaster levels, you can cast a divine spell as an arcane spell, or vice versa. This enables you to bypass arcane spell failure due to armor, or gain additional benefit from spell that functions differently for a divine caster instead of an arcane caster, such as true seeing or magic weapon.

Spells changed with this feat are often confusing to whose who haven’t studied Mulan magic. Spellcasters who don’t have this feat suffer a –4 penalty on attempts to counterspell or dispel this spell, and they must succeed at a caster level check (DC 11 + spell level) to detect the spell with detect magic.

The actual source of the spell’s power doesn’t change, nor does its means of preparation. You are merely weaving the strands of magic together in an unconventional way that makes the spell behave somewhat differently.

My questions would be:

1. Does a pure wizard with this feat qualify for Theurge type classes, as he can cast divine spells at the same level (eg: Geomancer or Mystic Teurge after level 3)?
2. [this question is moved to a separate question]

Answer 1

1. Does a pure wizard with this feat qualify for Theurge type classes, as he can cast divine spells at the same level (eg: Geomancer or Mystic Teurge after level 3)?

Unknown. Southern Magician says,

The actual source of the spell’s power doesn’t change,

which CustServ has claimed means that it can’t qualify for mystic theurge. But CustServ is notoriously wrong notoriously often, and in any event there is nothing in the rules as written that explains what “power source” really means or what the implications of this statement are.

Whether or not a prestige class that advances a divine spellcasting class could advance the wizard class if that wizard has Southern Magician is even less clear—we have no official, strict definition of “divine spellcasting class.” The issue of “power source” is also a concern here, regardless of how you define “divine spellcasting class.”