Posted this in the other thread, don't know which is the "right" one.
I'm glad Brad is thinking on these terms. It bodes very well for the fun-ness factor. It seems to me a core choice is one that sets the tone for at least the next few minutes of the game, if not longer. Air vs. land would be such a choice. T1 vs. T2 would be. Orbital vs unit spam vs defensive buildings another.
I'm having some trouble with factory vs. expand as a core choice in 0.71. If you choose to build the factory right away, you forfeit your ability to gain a region before the neutrals spawn. This path puts your unit production about 15 seconds ahead of the expand choice, but not really because you have to send units to grab that region eventually. As such, it is never better to build the factory first, so it's not really a choice.
There IS a choice for the expand option though: metal or radioactives? The former may allow you to sustain spamming T1 units and weak defenses for longer, whereas the latter would give you earlier access to more quanta and advanced units. This choice could be made starker by giving the player a one-time per region bump in the associated resource the instant they capture a region (say 50 for radioactives, 100 for metal). This would also make the subsequent order of expansion choices more impactful, and would help with some of the early game economy stall problems.