I know what the RAW are but after reading a bunch of threads that mention "adding" vs "increasing" vs "whatever", I am confused! Could one of you rule-gurus please explain how different Defense values are calculated beyond "take the highest" (provided there are other rules beyond that)?

If there are talents or item qualities that state "+1 defence" or "add defence" then you increase the character's defence. The only thing that typically doesn't stack with pre-existing defence is taking cover, because it "sets your ranged defence to 1" and dual-wielding weapons with the +1 defence quality (you only get one). Adding, increasing or +1-ing all add up, it's just when the text specified that your defence is set to a specific number that it doesn't stack.

Still confused. So, armored robes, a personal shield, a Defensive weapon, a +1 Melee from FSEx and a defensive boost from a lightsaber Talent would be a 5 Defense?

The rules are kind of simmering chaos. Essentially armor sets a Defense rating and it is typically general defense. Then more or less everything else modifies it. So the armor and shield wouldn't stack but all other kinds of things would add to that. It also looks like they are changing cover to +1 Ranged defense with F&D beta.

Defense could use a game system wide errata update. It's kind of a come as you are party depending on what book you are looking at.

In an effort to fix things, they may have just re-confused me.

Now everybody's confused!

Yes, I think we could really use a step-by-step breakdown and clarification about how defense stacking works.