Congratulations on your new additions!
Like you said, bonding is very important and it sounds like you're doing a good job with your 2 boys!
The 2 issues you mentioned, are sensitive ones for me because my first glider was very underweight and she also had a calcium deficiency. After changing her diet, her numbers improved dramatically. I found a scale at Walmart (measures in grams) for under $20 so I can keep track of her weight. Most people here will tell you that all pellets are bad for gliders but I do believe much progress has been made over the years and I've talked to several exotic vets who told me about the higher quality pellets. HPW and BML are 2 really good diets out there and seem to be nutritionally balanced. Sounds like you're already feeding them some of the important foods in addition to a regular staple....especially fruits and veggies. Chicken, eggs, and yogurt are great options as well.