Well, first consider yourself VERY lucky that it is covered by your health insurance. I paid out of pocket for Neocate for 9 months. Luckily we have made the switch to whole milk and done well!
I would recommend warming it like you would breastmilk, in a bowl of warm-hot water. My doctor said that microwaving can change the proteins in milk and we were having enough problems, I wanted to eliminate anything more. But if anyone else chimes in here they may say microwaving is fine. We never used any RTF, always powdered.