You can't put things in your soil and expect the plant to "taste" like whatever you use. I mean if that's the case then May J would really taste like crap if the plant absorbed everything from the soil for taste...Yuk!!
The warmer is just to make it humid under there combined with the water. If you're using the doom I would keep water in it or turn it off if not in use. It looks nice.
Looking good!! Maybe,but look;why not just veg about another month (if indoors) under 18/6 and veg another month? I know then you'll definitely will be at an ounce plus.
They look NICE!! The yellowing or lime green is the plant is using the stored energy from day before to build. You usually see that on the plant when you turn your lights on or in the morning time for outdoors.