Be advised, I don't have much experience in saving in SP. I've only done it a few times, mainly because I have a good internet connection and can easily just run a dedicated server on my own machine.

So this is not scientific. This is just a guess.

If I was you, I'd focus on smaller scale missions. I'd especially be weary of using even the default values in the Military Commander Civilian Objective, and the Military Commander Military Objective modules. My best guess is, these two modules will be the ones you'll need to focus on the most. And perhaps Military Logistics and going easy on CQB too.

In my brief testing, Combat Support, Military IED, Virtual AI, Civilian Population/Placement and all of the other feature enhancement modules seem ok when loading a save.

The kind of missions I make for SP are designed for short-ish sessions. ALiVE functions more as a backdrop around the objectives than it does center stage. For example, let's say you made an HVT mission or hostage rescue mission that you crafted yourself using task modules and triggers and stuff. In this situation I'd use ALiVE Required, Virtual AI, Combat Support (for transport), CQB, and I'd go very easy on the profiles I'd spawn in the mil/civ obj modules.

Now, if you just wanted to use ALiVE only and not have to handcraft stuff, I'd say maybe give an Insurgency mission a try, but going really easy on the initial spawns. Maybe even hand place them (making sure to virtualize them) and set the Assymetric Commander's mil/civ obj modules to "objectives only" and see how it goes.

It's hard to say what 64-bit will bring to the table, but I'd advise not to try doing a full scale full map Invasion vs Occupation commander mission where you use the default module options. I mean by all means, if you're frisky see what happens but I can't imagine it would go well when you tried to load it.