[thejeff]

How do you survive long enough (and expand and get enough gems and gold to recruit mages to research) to get to Construction 8 without researching anything else?

No summons, your mages are almost useless on the battlefield. Some nations could get by just equipping their thug-like recruitables, though they couldn't self-buff. Most would have to rely on normal troops without mage support, and I suppose a pretender SC. Who can't be optimized as an SC since you need him to cover whatever paths you don't have natively for the Chalice and Tartarians.
And you've then got to go to Conjuration 9 to summon Tartarians.

Sure, if you do you'll be in good shape for the end game, but aren't they usually serious wars long before then? Or is this a turtle strategy? Whoever hides without fighting and gets away with it wins?