Hey dear always feed on demand incase your baby doesn't wake up after 4 hrs then you should wake up your baby n feed.. and that red rashes are called milia rubra and it's very common in new borns no need to apply anything on rashes it will go by itself don't worry

I suggest two hours of gap ..for full feed ..Also the urination n potty ..feed after that ..if the baby is hungry or crying ..

It takes almost 1 n half hour for the baby to digest the milk. Keep 2 hrs gap in each feeding. Also make sure after the feed baby's tummy is full n u burp him. Feeding them frequently disturbs their stomach. Make a feeding schedule so your baby will become used to it slowly. For the red rashes, apply malai means cream on his face but don't rub hard. It will help to reduce the rashes.

Feed on demand, only when the baby asks for it in its own way, However if you see huge time gap like say more than 5 hrs then wake up the baby gently and feed. If you keep feeding the baby waking up every time then your baby will not know what's hunger is like and he/she will expect you to wake up. It will become a habit so always feed on demand.