Chicken wire might not be the best to use. It can sometimes have sharp edges and can scrape, cut, and hurt your beardie. Also, wouldn't the holes be easy for your little one to climb through?
Home depot sells some stuff that is covered in a black material. It's a lot like screen, but the holes are a little larger. You can find it in the pet section with the chain link fencing. I can't remember the name of it, but works great for an outdoor cage. The holes are small enough to prevent lightning bugs/fireflies from getting through....which will kill your dragon very quickly if he eats one.
If your thinking of making a vivarium inside, wire/screen probably isn't a good idea.....as it makes it hard to maintain a heat gradient inside.
Yes....playmates are a bad idea. As humans we seem to want to pair things up....this is bad with beardies. It usually leads to dominance, stress, fighting, and injuries.
Yes, mealworms are bad. And yes....you need a much larger tank. One that allows for your temps to have a gradient. 85F on the cool side to 105-115 in the basking area at the other end. (Note - the stick thermometers can be off by as much as 20 degrees.....it's best to use a temp gun or a thermometer with a probe to monitor temps.)
Sexing is easiest when they get a little older. But the best way to check is to put your beardie flat on a table. Lift the tail gently to almost a 90 degree angle from its body. If you see two lumps on the sides at the base of the tail by the vent....it's a male.....one lump in the middle=female. I tried sexing ozzy holding him up and looking underneath him....it won't work that way. You gotta had them sitting on their bellies for it to be accurate.