Hi there, everything's looking good now ! Sounds like you have a great little dragon, healthy and eating well.
You've probably thought [ like most new owners ] that the " stress marks " mean the dragon is stressed, unhappy but that's not true. Those marks can come + go anytime, even with a perfectly happy dragon because they can also have them due to plain old energy level/excitement and other reasons. No need to worry. And as for the t8 light bulb that you mounted in the tank, they should be 8-10" away so your distance is fine. Any closer than that is actually a bit too close. I bred dragons for many years, the bulbs back in the 90's were even weaker but no one had them closer then 8" or so and we brought up strong dragons with no MBD. Look forward t all the updates on your little guy who will grow very quickly at the rate he is eating.