Brawler Archive

In other words, if I have a ranged defense modifier from, say, the Pistol tree, and also have some ranged defense from 1H weapon tree, but AT THE MOMENT at fighting using my bare hands: will I get all the ranged defense bonuses?

Yes, all modifiers stack.

Note that Unarmed, 1-h and 2-h Toughness only work while using that weapon-type. Melee and Ranged Defense are always in effect, however.