No need to start flaming here
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As to the PrE: Not very wise to take no PrE at all. Both PM and AM are strong. Here, you can read up on AM enhancements and decide which schools you want to go for:
http://ddowiki.com/page/Archmage_enhancements
Keep in mind: The spell-based SLAs (not Arcane Bolt/Blast) can be metaed FOR FREE. So if you want to go force-based, you can be an Evocation AM and spam Maxed/Empowered/Quickened Magic Missile for 1 SP (warning, this would be considered a flavor choice however).
Concerning Enlarge: tbh, the only use for this spell which I can imagine is to one-shot beholders in quests like (e)VoN3 and invaders. I am sure there are more applications, but it is still very situational. If you don't take it, you can still attack mobs before they aggro on you. With fast movement and jump, you will be able to dodge most attacks.
Empower: Yes, you have it right, it's 25% over Maximize and costs quite a bit. However, you can apply it to SLAs for free ...
Several Spell schools: Nothing wrong with taking more than two spell schools. If you know why you are taking it and have all the other important feats covered.
Infant