DCs/CLs for intelligent magic items

[FrankfurtMainDM]

I can't seem to figure out how to calculate the difficulty classes and caster levels for an intelligent magic item's "powers". It's an intelligent +4 defending weapon with Int & Wis 14, Cha 10. It can use daze monster 3/day and detect magic at will. According to the book, it requires CL 15 to make the item).

I assume these are spell-like abilities. Logically, the DC is based either of the higher ability modifiers, since it probably couldn't 'cast' the two spells with an ability score of 10. So I guess that puts the DC for daze monster at 14 (10 + 2nd level spell + 2 Int (or maybe Wis) modifier). But the spell is subject to spell resistance, so how would I calculate the caster level? Is it the level of the maker? d20 + 15 is pretty likely to overcome the SR of a creature with 7 HD or less. Is it the minimum level of a spellcaster able to cast this spell? d20 + 3, for a 3rd-level wizard? Or maybe I've missed the info and it's something else entirely.

 

[Shin Okada]

Regarding DCs, the rule is a little bit vague about it.

From SRD,

Intelligent items can actually be considered creatures because they have Intelligence, Wisdom, and Charisma scores. Treat them as constructs. Intelligent items often have the ability to illuminate their surroundings at will (as magic weapons do); many cannot see otherwise.
Unlike most magic items, intelligent items can activate their own powers without waiting for a command word from their owner. Intelligent items act during their owner’s turn in the initiative order.

I guess they can use their mental ability scores as they are considered creatures in some manner. But frankly speaking, I am not sure if that is the strict interpretation of the by RAW.

Regarding CL, a magic item has one fixed CL and use that number for any effects it creates.

Unless CL is written in "prerequisites" entry, that is not a prerequisites for creating that magic item. It is just a typical CL of a certain magic item. But as a special rule, any intelligent magic item has minimum CL prerequisite of 15. So, an intelligent magic item always have 15+ CL.

When bought or found as a random treasure, most DMs usually assume that a magic item is a typical one and has written (typical) CL. But there always be exceptions.