shake/startled: this is call startle reflex. is very normal for a NB baby. dont have to do anything about it. some parents will swaddle their babies, you can try. dear son dont lik to be swaddled so we just leave him alone. =)
'Phlegm': is the breathing sound right? you heard the 'phlegm' sound thru his breathing? that's normal too. i 'pestered' pediatrician many times keep asking him is dear son having phlegm and he told me is normal and that'snot phlegm, dont need any medications at all.
NB babies nostrils are smaller, thus when they breathe, will produce such 'noise'. pediatrician told us the noise will goes off at 6-8mth old. dear son's one slowly got better after 4mth old and fully goes off after 6mth. UNLESS your baby cant breathe well due to this then you have to bring to a pediatrician immediately. to determine whether your baby is breathing well you can see the way he drinks his milk or suck pacifier(if he does). If he drinks milk and push the bottle out to use his mouth to breathe very frequent, means he might not be breathing well. and if he can suckle on his pacifier,means he dont need to use his mouth to breathe, means he is breathing well thru his nose =)
hope that helps =)