Wizard (Shadowcaster) Archetype: Shadow spells and cantrips question

[FallzQuick]

Shadow Spells (Su): At 1st level, a shadowcaster uses his shadow to prepare additional spells. He must spend his entire period of spell preparation in dim illumination to use this ability. He may prepare a number of additional spell levels of spells equal to the level of the highestlevel wizard spell he can cast. For example, if he can cast 6th-level wizard spells, he could prepare six 1st-level spells, two 3rd level-spells, or any similar combination that adds up to a total of six spell levels. These spells are stored in his shadow. He can only cast these spells when he is in an area of normal light or dim light. He gains Shadowtongue as a bonus language. This ability replaces arcane bond.

Is there any way to get cantrips from this? I know a lot of abilities let cantrips count as 1/2 lvl each. Is there a ruling on this?

[Captain Zoom]

PRD: "Spell Slots: The character class tables show how many spells of each level each can cast per day. These openings for daily spells are called spell slots. A spellcaster always has the option to fill a higher-level spell slot with a lower-level spell. A spellcaster who lacks a high enough ability score to cast spells that would otherwise be her due still gets the slots but must fill them with spells of lower levels."

You can memorize a lower level spell in a higher level slot.

PRD:

"Level
The next line of a spell description gives the spell's level, a number between 0 and 9 that defines the spell's relative power. This number is preceded by a list of classes whose members can cast the spell. A spell's level affects the DC for any save allowed against its effects."

Cantrips are listed as Level 0, so they are a spell of level 0.

PRD: "Cantrips: Wizards can prepare a number of cantrips, or 0-level spells, each day, as noted on Table: Wizard under “Spells per Day.” These spells are cast like any other spell, but they are not expended when cast and may be used again. A wizard can prepare a cantrip from a prohibited school, but it uses up two of his available slots (see below)."

Cantrips have a rule that says they are not expended when cast.

Put it all together and you get that you can memorize a 0-level spell in a 1st-level slot, and that 0-level spell, if a cantrip, is not expended when cast, so can be cast over and over.

Now, I will admit that the part about casting a cantrip over and over can reasonably be interpreted by a GM as meaning either (1) only cantrips memorized in the cantrip slots can be cast over and over but cantrips memorized in regular slots are expended when used, OR (2) if a cantrip is taken it can always be used over and over even if memorized in a regular spell slot.

I lean towards the latter, but I wouldn't get in my GM's face if they interpreted it the other way. So check with your GM before you go this route.