Meeting the requirements of Mystic Theurge

I plan on being a necromancer and the best way to control more undead is by being a Mystic Theurge. Its a challenging adventure which we are starting for the 3rd time, so I am not interested in going the normal route and taking 3 levels cleric and 3 levels of wizard so at 7th level I can take the first Mystic Theurge. The idea of using Mystic Theurge came from something I read and had not considered before.

So, the requirements are:

Skills: Knowledge (arcana) 3 ranks, Knowledge (religion) 3 ranks.

Spells: Able to cast 2nd-level divine spells and 2nd-level arcane spells.

Under advancing your character, the rules are clear, you must meet the requirements before you can take the prestige class, so I must meet the skill ranks first and spell casting first.

Since I dont know of any way to have 3 points in the skills except being level 3+ I have to be 3rd level.

Now the spell casting is the question.

So magic items are allowed in order to meet the requirement of feats, and those feats can be used to qualify for prestige classes. I wanted a better example of using magic items for prestige classes and found a comment thread where they leaned towards yes.

So, since magic items are allowed, if I took a level in cleric and wizard, and spent the last level somewhere, I would have access to both spell lists. This means that I am able to cast from wands with no check, and scrolls only require a CL check. This assumes no restricted schools and too low ability scores. So as long as I was carrying around scrolls of 2nd level divine and arcane spells, I technically meet the requirement of being able to cast 2nd level spells, because of the weird rule that you are the caster even when its being powered by a magic item. This answer actually has commentary under it based on this exact question.

Racial spells such as he Drow’s darkness could also meet the arcane requirement so cleric 3 and wizard 1 for MT at 5th is also possible. Turns out this is not possible.

So, based on this, would I be allowed to take mystic theurge at 4th level?