Checking unidentified items...

Correct if I'm wrong, which I probably am, but can't you take an unidentified item outside a city somewhere and equip it to test the mods? Like to determine if it is zealous, fortitude, something?

Yes, you can do exactly that and in some cases you don't need to take it out of town if you note things like fortitude.

Other mods like "while enchanted" or "in stance" or zealous/vampiric will require going out of town.

well you can never tell the damage bonus really could you?

Technically you could. It would just take alot of math and you still might get it wrong. It would require an average, which is never always right.

Unless it was something that you could use Wild Blow with (Melee Weapon) - because that skill will always cause a critical hit.

Still, if it was to pre-id something for potential unlocks, then you stand a good chance of being able to guess some upgrades. Sundering mods might be a bit difficult to figure out, same as knowing which element an upgrade might be.

Would it be worth it? If I had a gold fellblade, I'd spend half a day figuring it out to determine req and stats!

theres a thread that shows how to do this already...

Search, it's everywhere you want to be.

There's a thread about this in Riverside already with details and discussion on how to do so. Search for it, and you will find the answers you seek.