Sorry for the slow response.
I looked all thru my computer and couldn't find a chart on types of smoke. There should be plenty on line but IMHO hard woods are oak, hickory, mesquite they are used for longs smokes at first. Like beef or pork which will be longer smokess. I say pecan is the middle ground, its a darker color but not near the blatant smoke taste as hard smokes. Most everything else is a light smoke. tour fruits, nuts and softwoods. Heavy is the real hardwoods.
Thyme and bay are or were the Louisiana staples. Most of the old cajun homes had a bay tree for leaves, thyme plants around the house and sassafras tree in back ( the leave are ground to make file. As to how much just pick a place to start, add a teaspoon, add a tablespoon, more or less to find what you like and no one can do that but you and those you feed. For instance my Pop loved smoked meat, my mom wouldn't eat his. She liked mine because when smoking for her, like most ladies, they don't like heavy smoke, so I used light smoke. I vary my types, and my amounts, my temps. They all give you a different result on the same meat.
You said how juicy they were, that's the brine working. The herbs and spices are just flavor modifiers in the brine, so the size of the meat, as well as the amount of brine time and type (density) of the meat all matter with the way the brine is infused. But I am about to get long winded.
It appears you did a great job on those yardbirds. Now you just have to keep saying how you need to keep practicing to hone your skills. As long as they come out like that, you'll definately get to do more.