I also give Nestle rice cereal for my baby. When she started to eat cereal, I give her about 4-5 spoons of rice cereal with 3 ounce milk. It's fine. Sometimes she may not have poo poo everday. But the poo poo is not hard. She doesn't show any sign of 'hot air'.
Please note to give baby drinking water after he/she starts solid food.
Don't worry, I have always used breast milk to mix with cereal, you don't need to use formula milk. Try Yanlongma's suggestion, put the cereal in a bowl and then add milk afterwards. I have tried both Nestle and Healthy Times. Both are ok that way.
However if your baby is just starting to go on solid food, it does not need to be very thick. When I first started, the consistency is quite watery, almost like melted icecream's consistency. You can gradually add more cereal/less milk when your baby is more accustomed to solid food.