Both the frequency of stools and some mucus in stool is accepted and normal 

1-4 times passing stool....so not constipation And yes, A little bit of mucus can be normal

A stool frequency of1 to4 times daily is normal not constipation. So your child is perfectly normal However in case of other issues as crying during defecation ( which appears as difficulty in passing stool or constipation) you can consultation a pediatrician.

Yes little mucus everyday is normal. No need for any treatment. Please visit a pediatrician for check up if there is any other issues like weight loss etc

Can be 4 times a day And is normal

It’s normal, frequency is also normal

You can use a BPA-free feeding bottle for 4–6 months, but replace the nipple every 1–2 months or earlier if it shows signs of wear (cracks, thinning, or milk flow issues). Always clean and sterilize after each use. Alternative options like spoon feeding or using a paladai are also safe and help reduce nipple confusion and bottle dependency.

Nothing to be done if no other symptoms

Nothing to worry