I noticed that stamina recovery tooltip says that it affects the stamina regeneration during combat. So raising your stamina recovery does not affect the recovery rate out of combat?
It depends, from what I've seen. I don't understand the exact formulas they use, but percentage increases, like a skill that increases stamina regen by 30%, will increase out-of-combat and in-combat recovery by that percent. Flat increases, like a necklace that adds 55 stamina recovery, don't seem to affect out-of-combat recovery, though they do affect in-combat. I've been using the Harven's Extended Stats addon, which may not be updated for 1.6, so that's the basis for my conclusions.