Hey there, and WELCOME! I see some new names out here who seem to be going through the same thing...
To answer your first question; Yes, there is a definite potency/flavor and overall degradation in quality of your product when you run 1 bag, Wait, and then run another. The logic here is to not let your herbs cool down. And inflate as many bags as possible.
My advice would be to use the Reducing Chambers if you are someone who medicates off 1 bag and saves the rest for later extraction. That way the herb loss is kept at a minimal.
To answer your 2nd question: The orange grinder that comes with the unit gives you the perfect consistency for vaping. Use it!!
I just looked up the grinder and it looks like you shouldn’t be having any problems with your grind. There are many out there with this design and I used a similar Aerospaced on for years.
As for the green I find my AVB can be sometimes really light.. it also depends on the strain and as you start using your Volcano more you’ll see what I am talking about. But yeah, I’ve had bits of green but as long as I’m medicated I don’t feel like I’m wasting any and feel it is spent.
Try running more bags at once, and like Vitolo said shake the chamber... I do this in between bags.