is it possible to get more max magicka w/o using the mage?
The only way to get more is to use The Apprentice or The Atronach.
The Apprentice also gets a 50% weakness to magic, which svcks. The Atronach gets stunted magicka, which means you don't regenerate magicka, but have to get it some other way. However, they also get a 50% chance of absorbing the magicka from spells cast at them, so that's one way to do it. Plus absorbing the spell makes it harmless. BUT, playing an Atronach character is a bit of a challenge-- you really have to know what you're doing to succeed at it. And it's pretty obvious that you really don't know what you're doing, so I'd suggest The Mage.
You can also get a higher magicka maximum by playing a Breton or an Altmer, but you don't seem interested in that, so that's out.
And that's it. You can increase it with enchantments and you can increase it temporarily with potions, but the ONLY ways to permanently increase your base magicka is by playing a Breton or an Altmer or by picking The Mage, The Apprentice or The Atronach as a birthsign.
For your purposes, I'd go with The Mage. And with an Argonian-- for what you're trying to do, they have the best set of bonuses and the fewest penalties.
Just do it.