Isnt 2.45 A time too much for a 5 month old baby ?
No, not really. Average at 6mo (just turned) is 2:45-3hr and average at 4mo is 2hr so it increase by ~15min/fortnight - Some babies do longer A times than average, some shorter. If you're getting appropriate-length naps and baby is happy during the day, you're probably about right with the A times.
He is sure to have some discomfort from clubfoot braces.Anybody would have discomfort to have a metal bar binding his feet. But what can I do?
You can be understanding of his discomfort. Comfort him when he's in pain rather than showing him that you're not going to help him when he needs it. You could look into pain relief, especially for nighttime when he has less distraction from the pain and may have more pain from not being as able to move about as he is during awake time in the day.
Naps are better but we have many nightwakings ( he woke up every 1,5 hours last night) and he wont settle without feeding. Is it because of hunger? But I cant seem to make him nurse more in the day. He is a fast and distracted feeder. What should I do in terms of breastfeeding?
Feeding every 1.5hr through the night seems excessive to be just hunger at this age. I think the breastfeeding is a prop, probably. Does he have a pacified/dummy? How often are you feeding in the day? Have you tried a topup an hour after each main feed during the day (when you introduce solids, you would replace one at a time with solids)?
If you can't run the white noise all night, I would put him to bed for the night without any white noise. Any change in noise will potentially trigger him to wake, so turning it off can be a reason for him to wake.
I think in terms of NWs, I'd be inclined to try the following for a few days and see if it helps:
1. No white noise (even at BT)
2. Pain relief at BT - paracetamol/ibuprofen syrup according to his weight - if he then sleeps until it wears off and then he wakes frequently through the second half of the night, you have your answer regarding the role of pain in his wakings.