Welcome! I'm in MA as well, and adopted an Ibera Greek six weeks ago. This forum is full of the best knowledge around, I've learned so much since joining.
Check out the Lighting, Temperature, and Humidity section of the care sheet here:
https://www.tortoiseforum.org/threads/sticky-hermanns-tortoise-care-sheet-updated.101410/
Yes, definitely increase his temps. I'd be worried he gets a respiratory infection from the low temps and high humidity. I'm sure once you up his temps you'll see a huge increase in activity. Keep me posted!
What's the temp and humidity level in the travel box? Might be higher than in his enclosure, which would be why he's more active. Look into how to make a humid hide (they can be easy to makje and cheap, but a great benefit to babies). Make sure your temps are up in the enclosure, that will make...
While I know they all grow at different rates, 18g is the size of a hatchling or just a couple months old. I have a feeling the pet shop got papers or info mixed up somehow. I have a Greek that's 6 months and is currently 40g.
They aren't that small - not huge, its really compressed, but and once you soak them it really expands. I use them and was shocked at how much it makes.
I will try the cucumber. I tried adding a small amount to mazuri but I swear he knew it was in there because it was left untouched. It's like he eats around everything that has calcium in it, like he can smell it and wants nothing to do with it. I will trick him somehow :-)
He has one, but he just walks around and over it. I even tried breaking up pieces of it and putting it by his food, but nope he never touches it, not even a nibble.